[BUG] Cells which start with `%%html` lead to SyntaxError

[Dobatymo]

Describe the bug
%%html at the start of a cell can be used to output raw html. flake8-nb fails with E999 SyntaxError: invalid syntax.

To Reproduce
Have a cell like

%%html
<a href="#">asd</a>

in the notebook and run flake8-nb

Expected behavior
These cells should be ignored like other non-code cells.

Desktop (please complete the following information):

• OS: Windows 10 x64
• Version: Python 3.8.10 with flake8-nb==0.3.1

[s-weigand]

Thanks for reporting this bug!
For the time being, you can use the cell tag flake8-noqa-cell.

But I agree that cells with cell magic, which isn't ExecutionMagics line %%timeit or explicitly defines the code as python code (%%python) should be dropped by default.

[s-weigand]

@all-contributors please add @Dobatymo for bug

[allcontributors]

@s-weigand

I've put up a pull request to add @Dobatymo! 🎉