Improve README/CONTRIBUTING files

Use reStructuredText to allow HTML formatting while still maintaining
clarity in the raw text.

README.rst

@@ -0,0 +1,44 @@
+OBS Studio <https://obsproject.com>
+===================================
+
+What is OBS Studio?
+-------------------
+
+  OBS Studio is software designed for capturing, compositing, encoding,
+  recording, and streaming video content, efficiently.
+
+  It's distributed under the GNU General Public License v2 - see the
+  accompanying COPYING file for more details.
+
+Quick Links
+-----------
+
+ - Website: https://obsproject.com
+
+ - Help/Guides: https://github.com/jp9000/obs-studio/wiki
+
+ - Forums: https://obsproject.com/forum/
+
+ - Build Instructions: https://github.com/jp9000/obs-studio/wiki/Install-Instructions
+
+ - Bug Tracker: https://obsproject.com/mantis/
+
+   (Note: The bug tracker is linked to forum accounts.  To use the bug
+   tracker, log in to a forum account)
+
+Contributing
+------------
+
+ - If you wish to contribute code to the project, please make sure read
+   the coding and commit guidelines:
+   https://github.com/jp9000/obs-studio/blob/master/CONTRIBUTING.rst
+
+ - If you wish to contribute translations, do not submit pull requests.
+   Instead, please use Crowdin.  For more information read this thread:
+   https://obsproject.com/forum/threads/how-to-contribute-translations-for-obs.16327/
+
+ - Other ways to contribute are by helping people out with support on
+   our forums or in our community chat.  Please limit support to topics
+   you fully understand -- bad advice is worse than no advice.  When it
+   comes to something that you don't fully know or understand, please
+   defer to the official help or official channels.