docs: rewrite CONTRIBUTING.md to encourage early user feedback #29

Job	Run time
Public Integration Tests (Free Tier)	1m 2s
Documentation	57s
Formatting	11s
Clippy	1m 4s
Test (macos-latest, beta)	1m 18s
MSRV (1.75)	12s
Test (ubuntu-latest, stable)	1m 15s
Test (ubuntu-latest, beta)	1m 2s
Test (macos-latest, stable)	1s
Test (windows-latest, stable)	1m 8s
Test (windows-latest, beta)	1m 9s
	9m 19s

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