keyword rule: Spport for keywords inclusion from another language/file
Summary:
The goal is to reuse words from other definition files without having to copy them. For example, the list of CSS properties also in SCSS.
The presence of ## in the name of the keyword rule indicates that it is necessary to look for the list in another file (format: listName##languageName).
Test Plan: A quick test was done by removing the properties list from scss.xml and with properties##CSS as the keyword name.
Reviewers: Framework: Syntax Highlighting, cullmann, dhaumann, vkrause
Reviewed By: Framework: Syntax Highlighting, cullmann
Subscribers: kwrite-devel, vkrause, kde-frameworks-devel
Tags: Kate, Frameworks
Differential Revision: https://phabricator.kde.org/D14632