Helpers task290 improve on boarding docs

[sonniki]

#290

• Copied the missing docs/onboarding/kaizenflow.set_up_development_environment.how_to_guide.md from the kaizenflow repo
• Removed outdated references to ZenHub and ZH Epics and Pipelines
• Removed outdated references to Telegram
• Added docs/onboarding/all.must_read_checklist.md: a short-ish list of must-read docs that should be presented to anyone joining, be it with the full or light onboarding
  • TODO: Make sure all the docs in the list are onboarding-agnostic, i.e. they do not contain specific references to either the full onboarding process (e.g. developing on the server) or the light onboarding process (e.g. working as intern on Kaizenflow)
• Added a link to the must-read doc to docs/onboarding/all.onboarding_checklist.md
  • TODO: Create a "light onboarding checklist" doc with dev setup instructions for working on the laptop and the link to the same must-read list

[gpsaggese]

Great work! Let's keep the docs in shape

[sonniki]

@gpsaggese, UPD

• Added docs/onboarding/all.light_onboarding_checklist.reference.md
• Factored out the "technical" dev env set up part from that KaizenFlow doc into docs/onboarding/all.set_up_development_on_laptop.how_to_guide.md. This doc is now referenced in the light onboarding checklist.
• Renamed that KaizenFlow doc after moving the technical sections out -> docs/onboarding/kaizenflow.prepare_for_development.how_to_guide.md

[gpsaggese]

All good.

FYI One trick to avoid the monster PRs, when you realize that there is a problem, is to do a PR only running the linter and merge it. Then you pick up those changes from master and the PR has only your changes.