Docs: Add descriptions for some globals:

* `$wp_version`
* `$wp_local_package`
* `$required_php_version`
* `$required_mysql_version`

See #48303.
Built from https://develop.svn.wordpress.org/trunk@47230


git-svn-id: http://core.svn.wordpress.org/trunk@47030 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/class-core-upgrader.php

@@ -386,8 +386,8 @@ class Core_Upgrader extends WP_Upgrader {
 	 *
 	 * @since 3.7.0
 	 *
-	 * @global string $wp_version
-	 * @global string $wp_local_package
+	 * @global string $wp_version       The WordPress version string.
+	 * @global string $wp_local_package Locale code of the package.
 	 *
 	 * @return bool True if the checksums match, otherwise false.
 	 */