Guide on "Don't block the event loop" (#1478)
Guide on "Don't block the event loop" (#1478)

* WIP Guide on "Don't block the event loop"

For #1471

* More formal language, some examples

* Add indexOf

* Edits and more examples

- REDOS
- JSON DOS
- "Complex calculations without blocking the Event Loop"

* Typo

* Refresh sections: npm modules, conclusion

* Don't Block the Worker Pool

* Describe core module use of the Node Worker Pool

* Address review comments

- Rewrite the "A quick review of Node" section
- Remove "Event Handler" abstraction
- Provide more internal details
- Relax the "Offloading best practices"
- New task variation example: crypto.randomBytes
- Misc. formatting and bonus material

* Add link to node/17054

* Address review comments

yous/new.nodejs.org,yous/new.nodejs.org,phillipj/new.nodejs.org,nodejs/new.nodejs.org,nodejs/new.nodejs.org,phillipj/new.nodejs.org