Build the spec:
make -C doc/spec html
Open in your browser: doc/spec/build/html/index.html
Doxygen html is at: doc/spec/build/doxygen-html/index.html
There are pre-commit checks for spelling and broken links. To run it manually:
make -C doc/spec linkcheck make -C doc/spec spelling SPHINXOPTS=-q
The SPHINXOPTS is necessary to disable warning as errors, so you can see all the spelling errors instead of the first one. Add spelling exceptions to spelling_wordlist.txt. Do not add variable, class, function, etc to the exceptions. Spellcheck ignores them if they are properly delimited in the source doc.