update defineLanguage jsdoc

src/language/LanguageManager.js

@@ -468,7 +468,7 @@ define(function (require, exports, module) {
     /**
      * Defines a language.
      *
-     * @param {!string}               id                        Unique identifier for this language, use only letters a-z and _ inbetween (i.e. "cpp", "foo_bar")
+     * @param {!string}               id                        Unique identifier for this language, use only letters a-z, numbers and _ inbetween (i.e. "cpp", "foo_bar")
      * @param {!Object}               definition                An object describing the language
      * @param {!string}               definition.name           Human-readable name of the language, as it's commonly referred to (i.e. "C++")
      * @param {Array.<string>}        definition.fileExtensions List of file extensions used by this language (i.e. ["php", "php3"])