Document how we use git and GitHub (and maybe broader engineering guidelines)

[cpswan]

Is your feature request related to a problem? Please describe.
We're now using a range of GitHub templates, automations, bots, actions etc., which are well understood to those of use who've been around to see them implemented and get involved in the conversations about them. But all this stuff is likely to be confusing to new joiners.

Describe the solution you'd like
Add some READMEs (to a section of this repo or in a new repo) explaining how we use git and GitHub.

Describe alternatives you've considered
We could also broaden this out to cover other aspects of what we expect from engineers to make our engineering culture more explicit.

[cpswan]

Initial document published to https://github.com/atsign-foundation/.github/blob/trunk/atGitHub.md

[cpswan]

Dropping to 3 SP for remaining work and moving to PR44

[cpswan]

No progress on this in PR44, so pushing to PR45

[cpswan]

Again no progress in PR45 so pushing to PR46

[cpswan]

Need to get some @gkc bandwidth on this. Bumping to PR47

[gkc]

Other things we might want to cover

• Ever-increasing platform quality
• Tests
  • Unit tests vs functional tests vs e2e tests
  • Style guides
• Code quality
• Docs quality
• "You touch it, you tidy it"
• Backwards and forwards compatibility
• We need to say something about lints
  • Style guides
• Automated dependency management
  • If you pull on a thread, you have to go the whole way
• We want to get chunks of work done but the associated work to sustainably lift the quality also needs to happen
• This follow-up work needs to get into GH issues
• Also related to pubspec - clear definition of when we ^ dependencies and when we pin dependencies
• Substantial overview of what happens in PR reviews - expectations on both sides
• Engineering task lifecycle/process
• Need a place to discuss all of this stuff!
• Anti-patterns

[cpswan]

Some progress on this in PR47, but section headers need to be fleshed out in PR48

[cpswan]

We didn't get to this in PR48, so bumping to PR49

[gkc]

Too much other, more pressing, work came up during PR49.

[cpswan]

Given the volume of stuff on the hoist for PR50 I'm moving this to the backlog.