Customizing with other similar cell header formats?

[jdtsmith]

I've been working up a simple emacs recipe for fully syntactically valid source files arranged in blocks. jupytext would be ideal for conversion back and forth to notebook format. The idea is to use multi-line strings or block comments to wrap markdown blocks. This makes language servers, linters, etc. much happier. One interesting idea would be to allow slightly different header formats, somewhat like percent, but serving double duty as the nested outline section headers used in emacs, e.g.:

# * A Top-level cell
my_code()

# ** A second level cell [markdown]
r'''
-  A list
'''

# *** A 3rd level cell
print('3rd!')

Is there a convenient way to customize jupytext to target such a style?

One other thought regarding multi-line string cell_markers for Python. Ideally the starting marker would specify a raw string — r''' — so that checkers don't look inside the string and complain about invalid escape sequences (in LaTeX fragments, for example).