❇️ Add XML support

[jenskutilek]

Language Name

Extensible Markup Language

Tree-Sitter Grammar

https://github.com/tree-sitter-grammars/tree-sitter-xml

I will work on this

No

Additional Info (optional)

No response

[kkilchrist]

I've implemented XML support in PR #91 (along with R language support).

The implementation includes:

• Full syntax highlighting via tree-sitter-xml
• Support for extensions: .xml, .xsl, .xslt, .xsd, .svg, .plist
• XML-specific highlighting for tags, attributes, entities, processing instructions, comments, and CDATA sections

Tested and working for our use case (extracting symbols by name).