Release v0.3.0

• Offer to reload files when their contents changes
• Keep track of renamed or moved files
• Warn of deleted or otherwise disappeared files
• Add manual reload feature
• Accept drag & dropping files into main window
• Only accept "text/*" and catkeys MIME typed files
• Double-click left/right text view to open the file in the preferred app
• Make font size agnostic
• React live to changes of system colors
• Better distinguishable colors
• Use different colors for dark themed systems
• Add localization
• Thanks all translators for:
  Catalan, Dutch, French, Friaulian, German, Italian,
  Norwegian, Sardinian, Latin American Spanish, Turkish