[WIP] doc: build manpages for each module

Build manpages alongside JSON and HTML documentation. WIP to solicit feedback - does this direction make sense? Does anyone have opinions already on how this looks?

Fixes #8903 (closed)

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• documentation is changed or added
• commit message follows commit guidelines

Affected core subsystem(s)

doc

Open issues

• Tests
• Handle YAML data being where stability information usually is (would pull domain, punycode off the dontBuild list)
• Handle stability information not being present (would pull many files off the dontBuild list)
• Should I split up the node_modules change into a separate commit? The diff is kinda unreadable otherwise
• Move the "don't build this" metadata into the Markdown files themselves
• node-debugger(3), node-buffer(3), node-n-api(3), node-console(3), node-modules(3), node-process(3), node-timers(3) don't make much sense since they're not require()able modules
• Reduce the dontBuild list to what it actually should be (for example node-errors(3) really should be built, but crashes right now)
• Fix node-events(3) SYNOPSIS (and maybe other similar pages?)
• Some pages (like the OS module docs) duplicate information on how to require() the module
• Have node(1) point to things like node-debugger(3) when it makes sense
• Fix SEE ALSO in node(1)
• Should we have node-roadmap(1) and/or node-all(3), à la zsh?
• Do some of these belong in separate sections? E.g. node-debugger(1) instead of node-debugger(3)?
• Does BSDMakefile also need to be updated?
• The generated files aren't named properly (e.g. http.3 instead of node-http.3)
• Inline comments