How do I use pnpm?

[NullVoxPopuli]

I'd like to use pnpm instead of npm for a variety of reasons

npm v7 doesn't even have overrides/resolutions, and I need to test some PRs (e.g.: broccolijs/broccoli#499)

pnpm also has a correct peer dependencies implementation (and is very fast)

[kc0tlh]

This is now supported in our new VS Code editor!