Rust & Yacc/Bison: improve comments
Summary: Add ##Alerts and ##Modelines in comments. It also increases "kateversion" to 5.0 in yacc.xml, since it uses WordDetect rules.
Reviewers: Framework: Syntax Highlighting, dhaumann, cullmann
Reviewed By: Framework: Syntax Highlighting, cullmann
Subscribers: kwrite-devel, kde-frameworks-devel
Tags: Kate, Frameworks
Differential Revision: https://phabricator.kde.org/D17093