API to control what is ignored and `--no-ignore` ability to index everything

For nushell I'd like to be able to have a `--no-ignore` flag or `--ignore [*.rs *.md *.js]` parameter to control what is ignored during indexing.

I'm having a hard time telling exactly what is ignored now and I'm getting a lot of, "we have yyy number files in this tree but idx is only seeing zzz number of files". I'm not sure if something is wonky on my implementation, files are being ignored, an upstream bug here, or working as expected. Having a `--no-ignore` option would help narrow that down because then it should be reporting every file in a tree regarless of ignore state.

If there already is something, I apologize, I didn't see it here https://docs.rs/fff-search/latest/fff_search/ but I could be missing it.