docs: update calendar and link releases notes for 20.1.7

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6573>
diff --git a/docs/release-calendar.rst b/docs/release-calendar.rst
index 360cf50..6176bf4 100644
--- a/docs/release-calendar.rst
+++ b/docs/release-calendar.rst
@@ -30,9 +30,7 @@
 +--------+---------------+------------+-----------------+-----------------------------------------+
 | Branch | Expected date | Release    | Release manager | Notes                                   |
 +========+===============+============+=================+=========================================+
-| 20.1   | 2020-09-02    | 20.1.7     | Eric Engestrom  |                                         |
-|        +---------------+------------+-----------------+-----------------------------------------+
-|        | 2020-09-16    | 20.1.8     | Eric Engestrom  | Last planned release of the 20.1 series |
+| 20.1   | 2020-09-16    | 20.1.8     | Eric Engestrom  | Last planned release of the 20.1 series |
 +--------+---------------+------------+-----------------+-----------------------------------------+
 | 20.2   | 2020-08-19    | 20.2.0-rc3 | Dylan Baker     |                                         |
 |        +---------------+------------+-----------------+-----------------------------------------+
diff --git a/docs/relnotes.rst b/docs/relnotes.rst
index 8883065..e623b52 100644
--- a/docs/relnotes.rst
+++ b/docs/relnotes.rst
@@ -3,6 +3,7 @@
 
 The release notes summarize what's new or changed in each Mesa release.
 
+-  :doc:`20.1.7 release notes <relnotes/20.1.7>`
 -  :doc:`20.1.6 release notes <relnotes/20.1.6>`
 -  :doc:`20.1.5 release notes <relnotes/20.1.5>`
 -  :doc:`20.1.4 release notes <relnotes/20.1.4>`
@@ -312,6 +313,7 @@
    :maxdepth: 1
    :hidden:
 
+   relnotes/20.1.7
    relnotes/20.1.6
    relnotes/20.1.5
    relnotes/20.1.4