Mention where vsce is installed (#5622)

utils/vscode/development.md

@@ -14,6 +14,9 @@ NodeJS is required to build the extension. You will also need to install `vsce`:
 npm install -g vsce
 ```
 
+This installs `vsce` to `/usr/local/bin/vsce`. Ensure that `/usr/local/bin` is
+in your `$PATH` environment variable to use it.
+
 ## Common operations
 
 -   Build and install: