Mention Tinymist instead of Typst LSP (#5193)

Author: laurmaedje

tools/support/README.md

@@ -4,8 +4,8 @@ a syntax definition and a language configuration for comment toggling,
 autoclosing etc.
 
 The extension was created for development purposes only. It is not maintained
-and its grammar is not 100% accurate. For a more actively developed extension
-see the third-party [Typst LSP](https://github.com/nvarner/typst-lsp).
+and its grammar is buggy. For a more actively developed extension see the
+third-party [Tinymist extension](https://github.com/Myriad-Dreamin/tinymist).
 
 ## Installation
 The simplest way to install this extension (and keep it up-to-date) is to add a