README.rst: Add Crowdin progress badge

This adds a badge to the README that shows the progress of the OBS Studio Crowdin Project. This is a more obvious link to the translation project as it is only mentioned in the description far below.

README.rst

@@ -17,6 +17,10 @@ OBS Studio <https://obsproject.com>
    :alt: OBS Studio Discord Server
    :target: https://obsproject.com/discord
 
+.. image:: https://d322cqt584bo4o.cloudfront.net/obs-studio/localized.svg
+   :alt: OBS Studio Translation Project Progress
+   :target: https://crowdin.com/project/obs-studio
+
 What is OBS Studio?
 -------------------