- Added [Settings](https://github.com/DragoonAethis/itch-dl/wiki/Configuration-Files) - it's now possible to permanently set an API key instead of providing it every single time on the command line. (Using the config file is not mandatory.)
- itch-dl now depends on Pydantic for config file validation.
- The User Agent is now being set to `python-requests/{version} itch-dl/{version}` by default. This is configurable.
- Misc cleanups, typing fixes and more descriptive error messages with wiki links.