added a postinstall note

Author: bmuenzenmeyer

README.md

@@ -18,6 +18,8 @@ Or add it directly to your project's `package.json` file and run `npm install`
 
 During installation, the plugin is added as a key to the `plugins` object in your main Pattern Lab project's `patternlab-config.json` file
 
+> If you don't see this object, try running `npm run postinstall` within the root of your project.
+
 ## Configuration
 
 Post-installation, you will see the following in your `patternlab-config.json`:

postinstall.js

@@ -1,3 +1,4 @@
 console.log('Pattern Lab Node Plugin - "plugin-node-tab" installed. ');
+console.log('You may have to run `npm run postinstall` from your console as well.');
 console.log('Configure or disable this plugin inside your patternlab-config.json file.');
 console.log('Add tabs to the Pattern Lab UI by adding file extensions to the "tabsToAdd" array on the plugins.plugin-node-tab.options object.');