DOC Add cross references to widget contributions

[lucyleeow]

Depends on napari/docs#286

Adds references to new 'creating widgets' section and gallery and cookiecutter to widget contributions page.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (595b088) to head (9f2e25f).
Report is 4 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##              main      #331   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           37        37           
  Lines         2750      2750           
=========================================
  Hits          2750      2750           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[psobolewskiPhD]

You can edit OP with
Depends on
To make the CI action check it.

[lucyleeow]

Did it work ?

[psobolewskiPhD]

Ha! I got my repos confused. This one doesn't have the action to check for dependency between PR.
Could be worth adding though since things in this repo might depend on things being merged in napari/napari or napari/docs in this case.

[lucyleeow]

@psobolewskiPhD I think this is ready for review now that the dependency has been merged 🙏 Thank you!

[DragaDoncila]

Awesome, thanks @lucyleeow