Added license and documentation files
Signed-off-by: Steve Winslow <swinslow@gmail.com>
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000..9ea5b45
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,63 @@
+SPDX-License-Identifier: CC-BY-4.0
+
+# Contributing
+
+All contributions should include a "Signed-off-by" line in the commit message.
+
+This indicates that the contribution is made pursuant to the [Developer Certificate of Origin (DCO)](https://developercertificate.org/), a copy of which is included below.
+
+## License information
+
+New **code files** should include a [short-form SPDX ID](https://spdx.org/ids) at the top, indicating the project license for code, which is Apache-2.0 OR GPL-2.0-or-later. This should look like the following:
+
+```
+// SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+```
+
+New **documentation files** should include a [short-form SPDX ID](https://spdx.org/ids) at the top, indicating the project license for code, which is CC-BY-4.0. This should look like the following:
+
+```
+SPDX-License-Identifier: CC-BY-4.0
+```
+
+## Developer Certificate of Origin (DCO)
+
+```
+Developer Certificate of Origin
+Version 1.1
+
+Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
+1 Letterman Drive
+Suite D4700
+San Francisco, CA, 94129
+
+Everyone is permitted to copy and distribute verbatim copies of this
+license document, but changing it is not allowed.
+
+
+Developer's Certificate of Origin 1.1
+
+By making a contribution to this project, I certify that:
+
+(a) The contribution was created in whole or in part by me and I
+ have the right to submit it under the open source license
+ indicated in the file; or
+
+(b) The contribution is based upon previous work that, to the best
+ of my knowledge, is covered under an appropriate open source
+ license and I have the right under that license to submit that
+ work with modifications, whether created in whole or in part
+ by me, under the same open source license (unless I am
+ permitted to submit under a different license), as indicated
+ in the file; or
+
+(c) The contribution was provided directly to me by some other
+ person who certified (a), (b) or (c) and I have not modified
+ it.
+
+(d) I understand and agree that this project and the contribution
+ are public and that a record of the contribution (including all
+ personal information I submit with it, including my sign-off) is
+ maintained indefinitely and may be redistributed consistent with
+ this project or the open source license(s) involved.
+```
diff --git a/LICENSE-code.txt b/LICENSE-code.txt
new file mode 100644
index 0000000..a486815
--- /dev/null
+++ b/LICENSE-code.txt
@@ -0,0 +1,550 @@
+The spdx-go source code is provided and may be used, at your option,
+under either:
+* Apache License, version 2.0 (Apache-2.0), OR
+* GNU General Public License, version 2.0 or later (GPL-2.0-or-later).
+
+Copies of both licenses are included below.
+
+ Apache License
+ Version 2.0, January 2004
+ http://www.apache.org/licenses/
+
+ TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+ 1. Definitions.
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+
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+
+ END OF TERMS AND CONDITIONS
+
+ APPENDIX: How to apply the Apache License to your work.
+
+ To apply the Apache License to your work, attach the following
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+
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+
+= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
+
+ GNU GENERAL PUBLIC LICENSE
+ Version 2, June 1991
+
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+ Preamble
+
+ The licenses for most software are designed to take away your
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+ GNU GENERAL PUBLIC LICENSE
+ TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+ 0. This License applies to any program or other work which contains
+a notice placed by the copyright holder saying it may be distributed
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+
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+
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+ when run, you must cause it, when started running for such
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+
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+
+ END OF TERMS AND CONDITIONS
+
+ How to Apply These Terms to Your New Programs
+
+ If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+ To do so, attach the following notices to the program. It is safest
+to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+ <one line to give the program's name and a brief idea of what it does.>
+ Copyright (C) <year> <name of author>
+
+ This program is free software; you can redistribute it and/or modify
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+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
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+
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+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+Also add information on how to contact you by electronic and paper mail.
+
+If the program is interactive, make it output a short notice like this
+when it starts in an interactive mode:
+
+ Gnomovision version 69, Copyright (C) year name of author
+ Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+ This is free software, and you are welcome to redistribute it
+ under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License. Of course, the commands you use may
+be called something other than `show w' and `show c'; they could even be
+mouse-clicks or menu items--whatever suits your program.
+
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a "copyright disclaimer" for the program, if
+necessary. Here is a sample; alter the names:
+
+ Yoyodyne, Inc., hereby disclaims all copyright interest in the program
+ `Gnomovision' (which makes passes at compilers) written by James Hacker.
+
+ <signature of Ty Coon>, 1 April 1989
+ Ty Coon, President of Vice
+
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diff --git a/LICENSE-docs.txt b/LICENSE-docs.txt
new file mode 100644
index 0000000..3435082
--- /dev/null
+++ b/LICENSE-docs.txt
@@ -0,0 +1,399 @@
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diff --git a/README.md b/README.md
new file mode 100644
index 0000000..c833cd1
--- /dev/null
+++ b/README.md
@@ -0,0 +1,50 @@
+SPDX-License-Identifier: CC-BY-4.0
+
+# spdx-go
+
+spdx-go is a collection of Go package intended to make it easier for Go
+programs to work with [SPDX®](https://spdx.org/) files.
+
+This software is in an extremely pre-alpha state (hence the "v0/" directory).
+
+## What it does
+
+spdx-go currently works with files conformant to version 2.1 of the SPDX
+specification, available at: https://spdx.org/specifications
+
+spdx-go provides the following packages:
+
+* *v0/spdx* - in-memory data model for the sections of an SPDX document
+* *v0/tvloader* - tag-value file loader
+
+## What it doesn't do
+
+spdx-go doesn't currently do any of the following:
+
+* work with files under any version of the SPDX spec *other than* v2.1
+* work with RDF files
+* output RDF or tag-value files
+* convert between RDF and tag-value files, or between different versions
+* enable applications to interact with SPDX files without needing to care
+ (too much) about the particular SPDX file version
+
+As a long-term goal, I am hoping to enable each of these. Code contributions
+are welcome!
+
+## Requirements
+
+At present, spdx-go does not require anything outside the Go standard library.
+
+## Licenses
+
+As indicated in `LICENSE-code.txt`, spdx-go **source code files** are provided
+and may be used, at your option, under *either*:
+* Apache License, version 2.0 (**Apache-2.0**), **OR**
+* GNU General Public License, version 2.0 or later (**GPL-2.0-or-later**).
+
+As indicated in `LICENSE-docs.txt`, spdx-go **documentation files** are
+provided and may be used under the Creative Commons Attribution
+4.0 International license (**CC-BY-4.0**).
+
+This `README.md` file is documentation, hence the CC-BY-4.0 license ID at
+the top of the file.
