Add ADR with actions decided upon during the OTP summit in Helsinki

[jessicaKoehnke]

This documents the decisions we made at the developer meeting during the OTP Summit in Helsinki

[henrik242]

👍🏻

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 72.11%. Comparing base (774bae4) to head (ede76b6).
⚠️ Report is 38 commits behind head on dev-2.x.

Additional details and impacted files

@@            Coverage Diff             @@
##             dev-2.x    #6866   +/-   ##
==========================================
  Coverage      72.10%   72.11%           
- Complexity     19526    19530    +4     
==========================================
  Files           2106     2106           
  Lines          78982    78982           
  Branches        8007     8007           
==========================================
+ Hits           56952    56955    +3     
+ Misses         19205    19203    -2     
+ Partials        2825     2824    -1     

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[VillePihlava]

Can you change the title to DevelopmentProcessConventions

[VillePihlava]

Once the updates to the contribution guidelines in PR #6869 have been merged, this decision should be referenced in CONTRIBUTING.md

[leonardehrenfried]

I agree with Ville's suggested renaming. Otherwise, this looks like a nice summary - thanks!

[VillePihlava]

The attendance record isn't that important anymore now that everyone is on the same page and everyone seems to agree.

I think you can remove most of the metatext, because this should be concise and we just want the decisions. The context and problem statement is enough context in my opinion. The date for the review should be entered into the calendar.

[t2gran]

I am happy with the PR as is, I added a few comments on minor issues. Some context information is useful - e.g. for a new developer reading this in 5 years from now.