Docs: Add documentation for the `$type` and `$mime_type` properties in `WP_Customize_Image_Control`.

Follow-up to [20319], [30309], [31698], [32023], [49679].

Props subrataemfluence.
Fixes #44411.
Built from https://develop.svn.wordpress.org/trunk@49680


git-svn-id: http://core.svn.wordpress.org/trunk@49403 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/customize/class-wp-customize-image-control.php

@@ -15,7 +15,20 @@
  * @see WP_Customize_Upload_Control
  */
 class WP_Customize_Image_Control extends WP_Customize_Upload_Control {
-	public $type      = 'image';
+	/**
+	 * Control type.
+	 *
+	 * @since 3.4.0
+	 * @var string
+	 */
+	public $type = 'image';
+
+	/**
+	 * Media control mime type.
+	 *
+	 * @since 4.1.0
+	 * @var string
+	 */
 	public $mime_type = 'image';
 
 	/**

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.7-alpha-49679';
+$wp_version = '5.7-alpha-49680';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.