docs: add ignore empty lines example

[guissalustiano]

Hey! I'm working with name on a personal project and I love it. The documentation really helped me and I would like to collaborate.

I write a small function to ignore comments in my parser, and I think it might be useful for other projects and show some combinators (I already have a question on stack overflow, but in the old version).

I still need to explain the example but I wanted an ok about the code and the example first.

[guissalustiano]

I write some test example too