RubyMine: How to add a german spell checker

Since the Spell checker german dictionary Show archive.org snapshot plugin is not maintained anymore, here is another way to use a german dictionary.

1. Install the Hunspell plugin and restart Ruby Mine
2. Run sudo apt install hunspell-de-de
3. Select /usr/share/hunspell/de_DE.dic in File > Settings > Editor > Spelling > Custom Directory +