[typespec-vs/typespec-vscode] Optimize err msg in typsespc extension

packages/typespec-vs/src/Exceptions.cs

@@ -27,6 +27,7 @@ public TypeSpecServerNotFoundException(string fileName, Exception? innerExceptio
             : base(string.Join("\n", new string[]
             {
                 $"TypeSpec server executable was not found: '{fileName}' is not found. Make sure either:",
+                " - Node.js is installed locally and available in PATH.",
                 " - TypeSpec is installed locally at the root of this workspace or in a parent directory.",
                 " - TypeSpec is installed globally with `npm install -g @typespec/compiler'.",
                 " - TypeSpec server path is configured with https://typespec.io/docs/introduction/editor/vs/#configure."

packages/typespec-vscode/src/tsp-language-client.ts

@@ -159,6 +159,7 @@ export class TspLanguageClient {
         logger.error(
           [
             `TypeSpec server executable was not found: '${this.exe.command}' is not found. Make sure either:`,
+            " - Node.js is installed locally and available in PATH.",
             ` - TypeSpec is installed locally at the root of this workspace ("${workspaceFolder}") or in a parent directory.`,
             " - TypeSpec is installed globally with `npm install -g @typespec/compiler'.",
             " - TypeSpec server path is configured with https://typespec.io/docs/introduction/editor/vscode/#configure.",