Document how to configure lsp settings.

Author: nojaf

README.md

@@ -33,3 +33,25 @@ After opening a ReScript file, open Cmd + Shift + P nav and find
 And to see the language server logs, open Cmd + Shift + P nav and find
 
     debug: open language server logs
+
+## Settings
+
+```json
+  "lsp": {
+    "rescript-language-server": {
+      "initialization_options": {
+        "extensionConfiguration": {
+          "askToStartBuild": false
+        }
+      },
+      "settings": {
+        "version": "1.71.0-next-441959d.0"
+      }
+    }
+  },
+```
+
+`initialization_options` are passed to the language server when it is started. They can be used to configure the language server. See [extensionConfiguration](https://github.com/rescript-lang/rescript-vscode/blob/441959d1feeaaffc1a589687758b1fbe1f649e72/server/src/config.ts#L5-L29)
+
+`settings` are specific to the Zed extension.
+With `version` you can point to a specific npm version of the [@rescript/language-server](https://www.npmjs.com/package/@rescript/language-server?activeTab=versions).