Merge pull request #49 from Automattic/update-readme

Migrating plugin instructions from old VIP Docs site to plugin's README.md

readme.md

@@ -1,21 +1,55 @@
-[![Run PHPUnit and PHPCS](https://github.com/Automattic/maintenance-mode-wp/actions/workflows/integrate.yml/badge.svg)](https://github.com/Automattic/maintenance-mode-wp/actions/workflows/integrate.yml)
-
 # Maintenance Mode
 
 Shut down your site for a little while and do some maintenance on it!
 
-Usage:
+## Installation and activation
+
+1. Add the plugin to the `/plugins` directory of an application's GitHub repository.
+2. Define the `VIP_MAINTENANCE_MODE` constant as true in `vip-config/vip-config.php`.
+3. Activate the plugin in the WordPress Admin dashboard Plugins screen.
+
+### Custom Template
+
+To add a custom template and messaging:
 
- - Add a template to your theme's root folder called `template-maintenance-mode.php`.
- - This should be a simple HTML page that should include the message you want to show your visitors.
+ - Create a template in your theme's root folder named `template-maintenance-mode.php`.
+ - This should be a simple HTML page that includes the message you want to show your visitors.
  - Note: the template should include `wp_head()` and `wp_footer()` calls.
- - Add the `VIP_MAINTENANCE_MODE` constant to your theme and set to `true`.
 
-## Installation
+### Additional Configurations
+
+Using filters and conditionals, you can customize the behavior of the Maintenance Mode plugin based on your needs. These options rely on the plugin being installed as described above.
+
+**Selectively Load Maintenance Mode**
+Configure Maintenance Mode to only display for a specific network site. Code similar to this example must be added to the `vip-config/vip-config.php` file:
+
+    $site_name = $_SERVER['SERVER_NAME'];
+    $lockdown = false;
+
+    if ( false !== strpos( $site_name, 'url-to-enable-maintentance-mode' ) ) {
+        // Set lockdown
+        $lockdown = true;
+    }
+    // Set maintenance plugin
+    define( 'VIP_MAINTENANCE_MODE', $lockdown );
+
+**Enable WordPress REST API**
+Configure Maintenance Mode to keep the WordPress REST API enabled even though the rest of the site is not accessible. Note that this code should be added to a file located within the `client-mu-plugins` directory:
+
+    // Generally allow API access
+    add_filter( 'vip_maintenance_mode_restrict_rest_api', '__return_false' );
+
+You can also choose to enable the REST API only in more narrow use-cases:
+
+    add_filter( 'vip_maintenance_mode_restrict_rest_api', 'x_mm_allow_api' );
+
+    function x_mm_allow_api( $default ) {
+    	if (my_check() ) { 
+                               return false;
+                 }
 
-1. Install the plugin.
-1. Set the `VIP_MAINTENANCE_MODE` constant to true.
-1. Activate.
+    	return true;
+    }
 
 ## Default template screenshots