Add troubleshooting step

tools-setup.md

@@ -96,7 +96,8 @@ Run:
 ```shell
 code
 ```
-VSCode is correctly installed if this opens a window, you can then close this window.
+VSCode is correctly installed if this opens a window, you can then close this
+window. If the `code` command is not recognized, try restarting your computer.
 
 ## Step 8: Generate a public/private SSH key pair