* macro to expand traits for host functions documentation
* other way: same Doc trait in seal modules
* added docs for macro, and remove `doc` attribute
* fmt
* Apply suggestions from code review
Co-authored-by: Alexander Theißen <alex.theissen@me.com>
* make docs to be generated into re-exported `api_doc` module; fix
unrelated elder docs;
* make it compile without `doc` attr passed to macro
* make alias functions indicated explicitly in docs
* tidy up docs
* refactored a bit
* macro to auto-add doc warning for unstable functions
* invoke macro with no doc generation by default
* addressed review comments
* hide api_doc module behind cfg(doc)
Co-authored-by: Alexander Theißen <alex.theissen@me.com>