I think we can respect users' `$HOME` directories and try not to pollute it with extra directories.

All we would need to do is to move the `.itch` directory to  `$XDG_DATA_HOME/itch`

A default setting for an environment variable (so that users can move the directory if they so choose) would look like this:
```sh
export ITCH_HOME="$XDG_DATA_HOME"/itch
```