Update documentation of highlight & RegExp
The highlighting documentation is updated, adding missing things and expanding the explanation of Dynamic rules:
Expand the explanation of the dynamic rules, detailing how they work and how to use them correctly. 3 examples of use are also added.
I consider this important, since at first I didn't understand how to use them and some XML files don't use dynamic rules correctly. For example, I have seen that some files add the dynamic attribute unnecessarily in some rules (as in the RegExpr rules where captures are made), add dynamic inside the element <context...>, which is obsolete, or try to inherit captures between contexts, which isn't allowed.
Add explanation of <emptyLines> and <spellchecking> within the group <general>.
Add explanation attribute noIndentationBasedFolding inside the element <context>.
In the Tips & Tricks section, it's recommended to use column="0" in RegExpr rules with ^ and use non-capturing groups in regular expressions.
The regular expression documentation contains some obsolete statements, so it is also updated:
- The special escape \w also includes underscores.
- POSIX character classes [:class:] are supported.
- Add description of capturing and non-capturing groups in the Assertions section.