fix: missing documentation, wich kind of glob is used for: very_good test --exclude-coverage

[dkbast]

Description

very_good test --help

   --exclude-coverage                A glob which will be used to exclude files that match from the coverage.

Since "glob" can be any of many implementations/interpretations and the expected *.g.dart did not seem to work it would be great to know which kind of glob can be used.

Expected Behavior
The help should provide an example glob and/or specify which pattern matching is used e.g. --exclude-coverage '.g.dart'

[dkbast]

It also looks like its not being applied, the following command still generates coverage files for *.g.dart, maybe I'm doing something wrong?

very_good test --coverage --exclude-coverage '\.g\.dart' --no-optimization

[dkbast]

Apparently the problem is that .g.dart only matches root level files and we need to write **/.g.dart to match files which are in folders - this can be closed, but maybe an example should be added for how to use this.

Using the exclude works, but introduces a whole new set of problems, because then all files with a part directive wont compile anymore.