Consider deprecation

[laurmaedje]

Hey there. We at Typst are grateful that you've developed Typst LSP, creating the first offline IDE experience for Typst. However, we've noticed that Typst LSP is not actively maintained anymore. In the meantime, the tinymist LSP extension has seen a lot of development, making it the better choice. However, your extension remains easier to find due to name, logo, download, and star count. With the best interests of Typst users in mind, we think it would be best to archive this repository, deprecate the VS Code extension and suggest to users that they migrate to Tinymist. Thanks again!