Add beta note to page Calum added

Author: hubwriter

docs/codeql/codeql-language-guides/codeql-for-ruby.rst

@@ -14,3 +14,5 @@ Experiment and learn how to write effective and efficient queries for CodeQL dat
 -  :doc:`Basic query for Ruby code <basic-query-for-ruby-code>`: Learn to write and run a simple CodeQL query using LGTM.
 
 -  :doc:`CodeQL library for Ruby <codeql-library-for-ruby>`: When you're analyzing a Ruby program, you can make use of the large collection of classes in the CodeQL library for Ruby.
+
+.. include:: ../reusables/ruby-beta-note.rst