allow to specify includes

[balrok]

As I wrote in #3, not everything can be expressed with negative lookahead/lookback in regexes. Also having the include feature, would make it way easier.

I hope its fine, that I also did some restructuring to avoid having such a big inner method.

I have it running with following settings:

  - exclude:
      include-glob:
        - "*.md"
        - "docs/*"
        - "assets/*"
      glob:
        - "*"

edit: removed ** since it has no effect