Want to exclude bower_components in .gitignore but have it included for autocomplete

### Prerequisites

* [x] Put an X between the brackets on this line if you have done all of the following:

### Description

I have a `.gitignore` file, this includes `node_modules` and `bower_components`
I do want to ignore bower_components for git,
but, I want `autocomplete-paths` to include it in its index...

**Reproduces how often:** 100%

### Versions

2.12.1

Start by examining how autocomplete-paths discovers and filters paths, using the repository's handling of .gitignore and the requested bower_components behavior as the entry points. Reproduce the issue with bower_components ignored by Git, then verify that it remains available to autocomplete without changing Git's ignore behavior.

Written by the indexing model from the issue text.