npm rebuild but no npm build... "IT'S A TRAP!"

[broofa]

Apparently npm build used to be a thing. However, support and documentation for this command quietly disappeared after npm@6. Meanwhile npm rebuild is still a thing, but is documented as:

"This command runs the npm build command on the matched folders"

There's a few problems with this:

1. Minor nit: npm build in modern versions of npm fails with 'Unknown command: "build"'
2. The behavior of npm build is effectively unspecified. There's the legacy docs, but those docs are old (three major versions back, now), and frustratingly terse. They allude to build being part of the "plumbing" of link and install, but don't elaborate on what that means or what build should or should not be used for.
3. "It'S a TrAp!" Since build isn't a thing, naive developers may assume they can define their own build behavior without running afoul of npm-native behavior. This can lead to issues like [BUG] npm rebuild runs build script, which has unexpected semantics uuidjs/uuid#698

Desired behavior: Hmm... I'm not sure. Given that build seems to have been deprecated, I would expect the same of rebuild as well, and any other related scripts that might rely on build.