paketkoll-v0.3.0

This is a massive release, as konfigkoll was introduced as a new command.
While this is not directly part of paketkoll, it had knock-on effects on the
way the source code is organized.

🚀 Features

• Add Makefile to help install things. This is needed to get man pages and
  shell completion files installed. They are not longer generated as part
  of the build script.
• Vendor deps by default (instead of linking them dynamically)
• Rework, only single files backend allowed
• Add paketkoll owns command to quickly find what package owns a file

🚜 Refactoring

• Split out print_packages
• Move backend traits to paketkoll_types
• Unify and format Cargo.toml files
• Revamp public API
• Use method for resolving string interning newtypes

📚 Documentation

• Reorganize README files

⚙️ Other stuff

• Fix typos and lints from RustRover