TinyMCE: make keyboard shortcuts more discoverable by adding them to the buttons tooltips and in the Formats drop-down.

Props mor10, azaozz.
Fixes #38063.
Built from https://develop.svn.wordpress.org/trunk@38897


git-svn-id: http://core.svn.wordpress.org/trunk@38840 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/css/editor-rtl.css

@@ -588,6 +588,7 @@ div.mce-path {
 .mce-menu .mce-menu-item-normal.mce-active,
 .mce-menu .mce-menu-item-preview.mce-active {
 	background: #0073aa; /* See color scheme. */
+	color: #fff;
 }
 
 .mce-menu .mce-menu-item-preview.mce-active {
@@ -650,6 +651,15 @@ div.mce-menu .mce-menu-item-sep,
 	margin-right: -2px;
 }
 
+/* Keyboard shortcuts position */
+.mce-menu.mce-menu-align .mce-menu-item-normal {
+	position: relative;
+}
+
+.mce-menu.mce-menu-align .mce-menu-shortcut {
+	bottom: 0.5em;
+}
+
 /* Buttons in modals */
 .mce-primary button,
 .mce-primary button i {