docs: use [1] instead of asterisk for footnote
While we're at it, make it a link as well.
Reviewed-by: Eric Engestrom <eric@engestrom.ch>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3443>
diff --git a/docs/license.html b/docs/license.html
index 3847917..a4ae66c 100644
--- a/docs/license.html
+++ b/docs/license.html
@@ -20,7 +20,7 @@
<p>
Mesa is a 3-D graphics library with an API which is very similar to
-that of <a href="https://www.opengl.org/">OpenGL</a>.*
+that of <a href="https://www.opengl.org/">OpenGL</a><sup>[<a href="#trademark">1</a>]</sup>.
To the extent that Mesa utilizes the OpenGL command syntax or state
machine, it is being used with authorization from <a
href="https://www.sgi.com/">Silicon Graphics,
@@ -38,8 +38,8 @@
</p>
<p>
-* OpenGL is a trademark of <a href="https://www.sgi.com/"
->Silicon Graphics Incorporated</a>.
+<a id="trademark">[1]</a>: OpenGL is a trademark of <a
+href="https://www.sgi.com/">Silicon Graphics Incorporated</a>.
</p>
