Add help wanted banner to readme

[jack-berg]

Mentioned this idea in the 8/1 java SIG. I think a more active approach to soliciting contributors may help.

If we merge this PR, I will get in the habit of actively using the help wanted label to indicate project priorities.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 90.03%. Comparing base (ddc9c91) to head (d30d87e). Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##               main    #6615   +/-   ##
=========================================
  Coverage     90.03%   90.03%           
  Complexity     6601     6601           
=========================================
  Files           730      730           
  Lines         19873    19873           
  Branches       1956     1956           
=========================================
  Hits          17893    17893           
  Misses         1387     1387           
  Partials        593      593           

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[jkwatson]

@jack-berg do you still want this? Happy to get it merged, but needs a rebase/main merge & Jason's suggestion is a good one, I think.

[jack-berg]

Its been a while since I thought about this. In the PR description I wrote "If we merge this PR, I will get in the habit of actively using the help wanted label to indicate project priorities." I haven't done that, and if I'm honest, don't know how good I'll be at doing this effectively on an ongoing basis.

I still do like a lot of the in this PR though. At the very least, its disarming and makes it easier to find introductory resources for anyone that may want to contribute.

Let me go ahead and update with the latest on main.