Support LSP document links (#56011)

Closes https://github.com/zed-industries/zed/issues/33587


https://github.com/user-attachments/assets/bbaea8a9-402e-485b-800e-2f4486142956

Release Notes:

- Supported LSP document links (enabled by default, use
`"lsp_document_links": false` to turn it off)

docs/src/visual-customization.md

@@ -382,6 +382,8 @@ TBD: Centered layout related settings
 
   // How to render LSP `textDocument/documentColor` colors in the editor.
   "lsp_document_colors": "inlay",        // none, inlay, border, background
+  // Whether to query and display LSP document links in the editor.
+  "lsp_document_links": true,
   // When to show the scrollbar in the completion menu.
   "completion_menu_scrollbar": "never", // auto, system, always, never