Expand documentation for typescript.tsdk

Fixes microsoft#42243

extensions/typescript-language-features/package.json

@@ -66,7 +66,7 @@
             "null"
           ],
           "default": null,
-          "description": "%typescript.tsdk.desc%",
+          "markdownDescription": "%typescript.tsdk.desc%",
           "scope": "window"
         },
         "typescript.disableAutomaticTypeAcquisition": {

extensions/typescript-language-features/package.nls.json

@@ -4,7 +4,7 @@
 	"reloadProjects.title": "Reload Project",
 	"configuration.typescript": "TypeScript",
 	"configuration.suggest.completeFunctionCalls": "Complete functions with their parameter signature.",
-	"typescript.tsdk.desc": "Specifies the folder path containing the tsserver and lib*.d.ts files to use.",
+	"typescript.tsdk.desc": "Specifies the folder path to the tsserver and lib*.d.ts files under a TypeScript install to use for IntelliSense, for example: `./node_modules/typescript/lib`.\n\n- When specified as a user setting, the TypeScript version from `typescript.tsdk` automatically replaces the built-in TypeScript version.\n- When specified as a workspace setting, `typescript.tsdk` allows you to switch to use that workspace version of TypeScript for IntelliSense with the `TypeScript: Select TypeScript version` command.\n\nSee the [TypeScript documentation](https://code.visualstudio.com/docs/typescript/typescript-compiling#_using-newer-typescript-versions) for more detail about managing TypeScript versions.",
 	"typescript.disableAutomaticTypeAcquisition": "Disables automatic type acquisition. Automatic type acquisition fetches `@types` packages from npm to improve IntelliSense for external libraries.",
 	"typescript.tsserver.log": "Enables logging of the TS server to a file. This log can be used to diagnose TS Server issues. The log may contain file paths, source code, and other potentially sensitive information from your project.",
 	"typescript.tsserver.pluginPaths": "Additional paths to discover TypeScript Language Service plugins. Requires using TypeScript 2.3.0 or newer in the workspace.",