added support for exclude-filters, nested parents and document titles

[mschmieder]

Hey Miles,

I stumbled upon your projects just a few days ago and did try to use it for our DevOps workflows. While it is already pretty neat, I was missing some important functionality to make it easier to integrate it into our pipelines. I took the liberty to modify your sources to support the following additional features

• Support nested parents
• Add exclude filter options to exclude files when using the tool in directory mode
• Add support to used the markdown document's title (# Title) instead of the filename

I added the necessary documentation into the README.md
There should not be any breaking changes, but since before this I never worked with go before - please have a good look at the code changes and let me know if I should do adaptions.

Best,
Matthias

[justmiles]

Hi Matthias - thanks for contributing!

This looks very useful. I'm out of town at the moment but will take a look at this when I get back.

[justmiles]

Thanks for the contribution @mschmieder!