Add missing step

Author: PatelUtkarsh

Diff for: contributing/engineering.md

@@ -60,6 +60,7 @@ Use WordPress's [wp-env](https://developer.wordpress.org/block-editor/reference-
 
 1. Install wp-env as mentioned above.
 2. Start with `wp-env start` (Assuming you have `wp-env` installed globally with updated PATH variable or use `npx wp-env start` to execute from repository's node_modules):
+3. Activate material plugin and theme.
 
 Setup the development tools using [Node.js](https://nodejs.org) and [Composer](https://getcomposer.org):