docs: Use RST format for README.

The majority of our documentation is written in RST, let's bring
the top level docs in line with that.

Presumably the top level docs are in MarkDown format, because this
is the default for new GitHub repostiroies, however GitHub can
render RST docs just fine.

Signed-off-by: Frode Nordahl <[email protected]>

README.rst

@@ -0,0 +1,44 @@
+========
+MicroOVN
+========
+
+MicroOVN is `snap-deployed OVN`_ with built-in clustering.
+`Open Virtual Network`_ (OVN) is an SDN platform that is commonly
+used with enterprise-grade cloud solutions.
+
+📖 Documentation
+----------------
+
+The `MicroOVN documentation`_ is found in the `docs`_ directory. It is
+written in RST format, built with Sphinx, and published on Read The Docs.
+
+💫 Project & community
+----------------------
+
+* `Join our online forum`_
+* `Contributing guidelines`_
+* `Code of conduct`_
+* `File a bug`_
+
+You can ask for technical help in the `Support`_
+sub-category in the above forum.
+
+📰 License
+----------
+
+MicroOVN is free software, distributed under the AGPLv3 license (GNU Affero
+General Public License version 3.0). Refer to the `COPYING`_
+file (the actual license) for more information.
+
+.. LINKS
+
+.. _snap-deployed OVN: https://snapcraft.io/microovn
+.. _Open Virtual Network: https://www.ovn.org/
+.. _MicroOVN documentation: https://canonical-microovn.readthedocs-hosted.com/
+.. _docs: https://github.com/canonical/microovn/tree/main/docs
+.. _Join our online forum: https://discourse.ubuntu.com/c/microovn/160
+.. _Support: https://discourse.ubuntu.com/c/microovn/support/164
+.. _Contributing guidelines: ./CONTRIBUTING.rst
+.. _COPYING: ./COPYING
+.. _Code of conduct: https://ubuntu.com/community/ethos/code-of-conduct
+.. _File a bug: https://bugs.launchpad.net/microovn/+filebug