docs: convert articles to reructuredtext

This uses the previously added scripts to convert the documentation to
reStructuredText, which is both easier to read offline, and can be used
to generate modern HTML for online documentation.

No modification to the generated results have been done.

Acked-by: Eric Engestrom <eric@engestrom.ch>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4630>
diff --git a/docs/release-calendar.rst b/docs/release-calendar.rst
new file mode 100644
index 0000000..1672f7d
--- /dev/null
+++ b/docs/release-calendar.rst
@@ -0,0 +1,44 @@
+Release Calendar
+================
+
+Overview
+--------
+
+Mesa provides feature/development and stable releases.
+
+The table below lists the date and release manager that is expected to
+do the specific release.
+
+Regular updates will ensure that the schedule for the current and the
+next two feature releases are shown in the table.
+
+In order to keep the whole releasing team up to date with the tools
+used, best practices and other details, the member in charge of the next
+feature release will be in constant rotation.
+
+The way the release schedule works is explained
+`here <releasing.html#schedule>`__.
+
+Take a look `here <submittingpatches.html#criteria>`__ if you'd like to
+nominate a patch in the next stable release.
+
+Calendar
+--------
+
++--------+---------------+---------+-----------------+-----------------------------------------+
+| Branch | Expected date | Release | Release manager | Notes                                   |
++========+===============+=========+=================+=========================================+
+| 20.1   | 2020-06-24    | 20.1.2  | Eric Engestrom  |                                         |
+|        +---------------+---------+-----------------+-----------------------------------------+
+|        | 2020-07-08    | 20.1.3  | Eric Engestrom  |                                         |
+|        +---------------+---------+-----------------+-----------------------------------------+
+|        | 2020-07-22    | 20.1.4  | Eric Engestrom  |                                         |
+|        +---------------+---------+-----------------+-----------------------------------------+
+|        | 2020-08-05    | 20.1.5  | Eric Engestrom  |                                         |
+|        +---------------+---------+-----------------+-----------------------------------------+
+|        | 2020-08-19    | 20.1.6  | Eric Engestrom  |                                         |
+|        +---------------+---------+-----------------+-----------------------------------------+
+|        | 2020-09-02    | 20.1.7  | Eric Engestrom  |                                         |
+|        +---------------+---------+-----------------+-----------------------------------------+
+|        | 2020-09-16    | 20.1.8  | Eric Engestrom  | Last planned release of the 20.1 series |
++--------+---------------+---------+-----------------+-----------------------------------------+