Update darcula.css
Update darcula.css

Adjust colors and font modifiers a little bit to make code more readable.
hackmdio/CodeMirror,codio/CodeMirror,jkaplon/CodeMirror,mtaran-google/CodeMirror,nightwing/CodeMirror,namin/CodeMirror,SidPresse/CodeMirror,namin/CodeMirror,notepadqq/CodeMirror,namin/CodeMirror,mtaran-google/CodeMirror,notepadqq/CodeMirror,pabloferz/CodeMirror,dperetti/CodeMirror,nightwing/CodeMirror,thomasjm/CodeMirror,notepadqq/CodeMirror,pabloferz/CodeMirror,SidPresse/CodeMirror,hackmdio/CodeMirror,thomasjm/CodeMirror,thomasjm/CodeMirror,hackmdio/CodeMirror,dperetti/CodeMirror,codio/CodeMirror,dperetti/CodeMirror,pabloferz/CodeMirror,mtaran-google/CodeMirror,codio/CodeMirror,nightwing/CodeMirror,jkaplon/CodeMirror,SidPresse/CodeMirror,wingify/CodeMirror,wingify/CodeMirror,jkaplon/CodeMirror,wingify/CodeMirror