Prepare release 0.5.0

[fendor]

Minor changes that are still not backwards compatible that we ought to get out in the wild.

Is there anything left to do that should be included in a new release?

• Include Bugfix in ChangeLog
• PR for ghcide Update to hie-bios 0.5.0 ghcide#552
• PR for HIE Update to hie-bios 0.5.0 haskell-ide-engine#1764
• PR for HLS Hls update latest hie bios haskell-language-server#100
• Bump version Add plugin to format .cabal files haskell-language-server#183
• Update Changelog to include latest changes Add plugin to format .cabal files haskell-language-server#183

cc @mpickering