NPM support is no longer global. Instead, it can now be configured

independently for each build type. This is important for allowing

editable and maybe sdist installs to use NPM, but to avoid it for Wheel

installs (which should not require any kind of Internet access to

build).
There are small changes to this:

The enabled flag is now install.
The python-dependencies is now python-modules, which better

  reflects how it's used.

Tested on a package using NPM. Verified I could control the NPM

behavior per-build.
Viewed the new docs.