Slightly adjust bootstrap regex

[colinwm]

The bootstrap regex here is a big excessive, e.g. it matches paths like:

/src/bootstraps/settings.js

which is human writen code, whereas I think it was intended to match things like

/src/bootstrap-custom.js

I made it so that the wildcard (which currently doesn't match dots) also doesn't match slashes, which restrains it a bit.

[look]

Please add some tests to this section to cover these cases:

https://github.com/github/linguist/blob/80f3531e8a1014a23f4606458e5a528053ed3cac/test/test_file_blob.rb#L243-L245

[colinwm]

@look good idea, done. Let me know if you have more test ideas

[look]

I'm a little shocked those tests worked since sample_blob usually has a corresponding file, but I guess in this case it doesn't need to read the content.

[lildude]

Oooof. Good catch. 🙇