There are some issues working with App Images related to a lack of consent related to how to be recognized by the App Launcher

## Proposal

Add some like `$APP_IMAGE_DIR` that should be better than listening to the changes over all `$HOME` files

## Why

- Right now, we have `.DirIcon` and `[app].desktop` files that cannot be recognized automatically by launchers, we need at least a recommendation to deal with this issue, like reading `$APP_IMAGE_DIR` or something like that
- The users mustn't deal with our issues
- There is a similar standard in Mac, these users used to add their apps to something like `$APP_IMAGE_DIR`, add something similar should improve their experience using this format