ḶÿṟïçṣŤṝấïŋɨṅğ Dĩåĉṛĭṱíčș sɣur because_curious

By default characters like äöü are ignored on lyricstraining.com. For example in German one can type 'konnte' instead of 'könnte' or 'fur' instead of 'für'. This is not only wrong, but also promotes learning wrong spelling of words. This extension allows requiring characters with diacritics. In other words the site will require 'könnte' when the lyrics has 'könnte' and typing 'konnte' will be treated like a mistake.