feat: Add field in config for find-fixture-files (#687)

[mpachin]

Fixes #687

[ovidiuch]

This is great!

I only have two mentions:

1. I appreciate the detailed README, but I'm afraid your scenario is too specific for the main README (it's already huge...). If you think it's valuable, you can move everything from "If your projects directory tree looks like this:" to a separate md file in the docs dir and link to it. Another option is to link to Add field in config for find-fixture-files method #687 as an example of where fileMatchIgnore can be useful.
2. This is a pet peeve of mine and I apologize if it comes off annoying. I noticed you've always kept fileMatch, exclude and fileMatchIgnore in the same order, which is cool. But can you change the order as follows please? fileMatch, fileMatchIgnore and exclude. I find this makes more sense since fileMatchIgnore comes in effect before exclude and it looks better visually for fileMatch* options to be grouped.

Thanks!

[mpachin]

Corrected 😊

[ovidiuch]

@mpachin Please test your new option on 4.4.0! 🎉

[mpachin]

@skidding just checked it in my project, everything works! 😃✨