I like removing the theme attributes, I think nobody uses those and they affect the binary format and clutter the docs.

I'd rather keep the deprecated html functions in case it's been a while since someone worked on a syntect project, it's just much friendlier. I really wish there was something like a deprecation attribute except it produced a build error instead of a warning.

One other option to keeping them is to keep them deprecated, but create a new empty enum type named Deprecated or something, and change those functions to take Deprecated as an argument, delete their bodies, and maybe also add `#[doc(hidden)]. Then check that when they're called they produce both a type error and a deprecation warning.