snap-docs: suppress non-consecutive header level increases - myst.header

[Rnfudge02]

I'm not sure if this is intentional, but there are a lot of warnings about non-consecutive header-level increases. If these increases are intentional for formatting purposes, we should look at suppressing this warning.

/home/docs/checkouts/readthedocs.org/user_builds/canonical-snap/checkouts/latest/docs/reference/interfaces/media-control-interface.md.rst:21: WARNING: Non-consecutive header level increase; H1 to H3 [myst.header]

[degville]

Thanks for flagging this. I think the right thing to do is to not skip header-level increases. I'll try to fix these warnings, and the others, as I go through the docs.