Docs: Improve various globals documentation, as per documentation standards.

Props upadalavipul, mukesh27, krupalpanchal, jigar-bhanushali.
See #57069, #56792.


git-svn-id: https://develop.svn.wordpress.org/trunk@54867 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-block.php

@@ -196,6 +196,8 @@ class WP_Block {
 	 *
 	 * @since 5.5.0
 	 *
+	 * @global WP_Post $post Global post object.
+	 *
 	 * @param array $options {
 	 *     Optional options object.
 	 *