Added an Example Ruleset

I’ve added an example ruleset for reviewers and raters (I don’t know what they are named) to test my linting language quickly without writing one themselves.
The program on the screenshot is a rule that flags headings that are not continuous from the previous headings (like jumping from H1 to H3).

Honestly, this language is way more expressive than I first thought. I thought it would be impossible to detect skipping levels, but it could.