Create ru-RU.plg_content_menuplus.ini

russian language file (please make folder for him - i don't know how )
Create ru-RU.plg_content_menuplus.sys.ini

russian language file
Update menuplus.xml

i have added 2 translations - english one was not incuded (and don't be translated ))) ), and russian one
russian language has been added
russian language has been updated
plg.xml has been updated
Merge pull request #4 from Cyberixxx/master

russian localization has been added