[WIP] doc: better stream docs

Adding better and more user friendly stream docs as per #8646

• Explanations and Examples
  • Stuff from https://github.com/substack/stream-handbook
  • Overview of https://nodejs.org/en/docs/guides/backpressuring-in-streams/
• Core npm modules
  • duplexify
  • end-of-stream
  • concat-stream
  • flush-write-stream
  • from2
  • parallel-transform
  • pump
  • pumpify
  • stream-each
  • through2

Any suggestions / feedback is extremely welcomed :) I'm definitely missing some npm modules.

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