Add Typst LSP config
This MR adds the default configuration for a Typst LSP (https://github.com/nvarner/typst-lsp).
Right now it doesn't work because the specified "highlightingModeRegex": "^Typst$"
cannot trigger. How can I add it? Typst file names end with .typ
. I'd like to add this as well and then this MR should be good to go.