Update README.rst

Fixed minor grammatical issues and updated Twitter to its current name (X) to reduce confusion.

Author: 97-42

README.rst

@@ -72,8 +72,8 @@ Community Chat
 ~~~~~~~~~~~~~~
 
 If you want to talk about CKAN development say hi to the CKAN developers and members of
-the CKAN community on the public `CKAN chat on Gitter`_. Gitter is free and open-source;
-you can sign in with your GitHub, GitLab, or Twitter account.
+the CKAN community on the public `CKAN chat on Gitter`_. Gitter is free and open-source, and
+you can sign in with your GitHub, GitLab, or X (formerly known as Twitter) account.
 
 The logs for the old `#ckan`_ IRC channel (2014 to 2018) can be found here:
 https://github.com/ckan/irc-logs.