Example and linter updates

[lickel]

This updates the example project to use a Codable object, since that is going to be far more useful for someone new.
Further, I synchronized the linter rules with our internal configuration and ran swiftformat.

Note: I have not made swiftformat auto-run anywhere at the moment.

[codecov-commenter]

Codecov Report

Merging #38 (29c03a2) into array-associations (51e81a9) will decrease coverage by 0.03%.
The diff coverage is 83.67%.

@@                  Coverage Diff                   @@
##           array-associations      #38      +/-   ##
======================================================
- Coverage               90.87%   90.84%   -0.04%     
======================================================
  Files                      30       30              
  Lines                    4922     4924       +2     
======================================================
  Hits                     4473     4473              
- Misses                    449      451       +2     

Impacted Files	Coverage Δ
...s/Sources/Requests/PaginatingFetchDefinition.swift	91.66% <ø> (ø)
...ibleSectionsFetchedResultsControllerTestCase.swift	99.15% <ø> (ø)
...Controllers/FetchedResultsControllerTestCase.swift	100.00% <ø> (ø)
FetchRequests/Tests/TestObject.swift	89.47% <ø> (ø)
.../Controller/FetchedResultsControllerProtocol.swift	81.31% <33.33%> (ø)
...Sources/Associations/FetchRequestAssociation.swift	76.44% <50.00%> (-0.17%)	⬇️
.../Sources/Controller/FetchedResultsController.swift	81.15% <66.66%> (ø)
.../CollapsibleSectionsFetchedResultsController.swift	86.85% <75.00%> (-0.41%)	⬇️
...tchRequests/Sources/SwiftUI/FetchableRequest.swift	88.05% <83.33%> (ø)
FetchRequests/Sources/BoxedJSON.swift	79.48% <100.00%> (ø)
... and 3 more

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