highlight Labels and References

[nineff]

• I have searched the issues of this repo and believe that this is not a duplicate.
• I have searched the discussions and believe that my question is not already covered.

Feature Request

Labels like <label> should be highlighted in a different color as the rest of the text/code, same with @-References like @label.
The Typst Webapp already does this, and I think the LSP should do this as well.

[nvarner]

This is already technically implemented, but it looks like I didn't implement it in a way supported by many themes. A fix will be merged soon. If it does not fix this issue for your theme, please open a new issue.