Rename the hook to "visible" and add documentation

src/jquery.uls.core.js

@@ -114,15 +114,26 @@
 	ULS.prototype = {
 		constructor: ULS,
 
+		// A "hook" that runs after the ULS constructor.
+		// At this point it is not guaranteed that the ULS has its dimensions
+		// and that the languages lists are initialized.
+		//
+		// To use it, pass a function as the onReady parameter
+		// in the options when initializing ULS.
 		ready: function () {
 			if ( this.options.onReady ) {
 				this.options.onReady.call( this );
 			}
 		},
 
-		afterShowing: function () {
-			if ( this.options.afterShowing ) {
-				this.options.afterShowing.call( this );
+		// A "hook" that runs after the ULS panel becomes visible
+		// by using the show method.
+		//
+		// To use it, pass a function as the onVisible parameter
+		// in the options when initializing ULS.
+		visible: function () {
+			if ( this.options.onVisible ) {
+				this.options.onVisible.call( this );
 			}
 		},
 
@@ -166,17 +177,17 @@
 				this.initialized = true;
 			}
 
-			// hide any other ULS visible
+			// hide any other visible ULS
 			$( '.uls-menu' ).hide();
 
 			this.$menu.show();
 			this.shown = true;
 
-			this.afterShowing();
-
 			if ( !this.isMobile() ) {
 				this.$languageFilter.focus();
 			}
+
+			this.visible();
 		},
 
 		i18n: function () {