RnR: CLI tool to batch rename files and directories

I found this tool a while ago when looking for a way to batch rename some files.

I've previously used Perl rename[1], but as it has no safeguards, I find rnr much more pleasant to use.

[1]: https://manpages.ubuntu.com/manpages/xenial/man1/rename.ul.1...

There are a lot of tools dedicated to this. My past favorite is vimv [1].

However, for me this operation is so rare that having a separate command just for mass-renaming files does not seem to be justified.

[1]: https://github.com/thameera/vimv