Compatibility issues with OTP-26.2 and later

[UncleGrumpy]

We have been using this fantastically helpful plugin to build the Erlang API documentation for the AtomVM project (https://github.com/atomvm/AtomVM). This allows us to include the Erlang API documentation with the rest of our written guides, and C API documentation generated with doxygen into a single unified "Read the Docs" theme. This would not be possible without the help of edown. Thank you.

We have run into problems building with recent OTP-26 (later than 26.2) and OTP-27. This is due to the edoc update in OTP2-26.2 that changed the behavior to emitting <code> instead of <tt>.

I am still quite a novice, so I am unsure how to fix this in a way that would not cause backwards incompatibility.