Enable up/down keys for navigating the ULS menu

src/jquery.uls.languagefilter.js

@@ -115,6 +115,14 @@
 						this.options.onSelect( query, e );
 					}
 
+					break;
+				case 38: // arrow up
+					this.options.lcd.navigateUp();
+
+					break;
+				case 40: // arrow down
+					this.options.lcd.navigateDown();
+
 					break;
 			}
 		},
@@ -163,6 +171,10 @@
 				results = [],
 				query = ( this.$element.val() || '' ).trim().toLowerCase();
 
+			// Reset the keyboard navigation index inside LanguageCategoryDisplay (lcd)
+			// before re-rendering the language options
+			this.options.lcd.resetNavigationIndex();
+
 			if ( query === '' ) {
 				this.options.lcd.setGroupByRegionOverride( null );
 				this.resultHandler( query, languages );