[feature] Execute a command on change detected

Some software only has a CLI interface and no way to communicate with it, would be superawesome to call some CLI command on change detected.

For example - Would be amazing if it could trigger a run of https://github.com/ArchiveBox/ArchiveBox

unfortunately it looks like it doesn't have a working API
- No REST API https://github.com/ArchiveBox/ArchiveBox/issues/496
- Looks like a working Python API https://docs.archivebox.io/en/latest/modules.html
- Can be driven by a CLI call https://github.com/ArchiveBox/ArchiveBox/wiki/Usage#CLI-Usage

In this case of archiving, i think it's important to be 100% sure the command is run/queued, so in this case maybe use some queue mechanism