@Kwpolska I appreciate your strong opinion on this, but I also think it should be based on Nikola's code practices:

* https://github.com/getnikola/nikola/blob/master/nikola/plugins/compile/markdown/__init__.py#L79
* https://github.com/getnikola/nikola/blob/master/nikola/plugins/compile/bbcode.py#L64
* https://github.com/getnikola/nikola/blob/master/nikola/plugins/compile/misaka.py#L71
* https://github.com/getnikola/nikola/blob/master/nikola/plugins/compile/textile.py#L60

I was also **not** suggesting of parsing HTML with regex, but to validate if the first paragraph is actually the meta comment before removing it. This is again an improvement over the above linked current implementation.