docs: new contribution guideline for client structure #5850

Job	Run time
Build / Build	8m 40s
Test Agent Local / test_agent_local	40m 20s
Test API / API Test Local	8m 13s
Test Packages / Test ./internal/billing	1m 42s
Test Packages / Test ./internal/encryption	2m 5s
Test Packages / Test ./internal/hash	1m 41s
Test Packages / Test ./internal/id	1m 43s
Test Packages / Test ./internal/keys	1m 45s
Test Packages / Test ./internal/resend	2m 0s
Test Packages / Test ./internal/clickhouse	3m 42s
Test Packages / Test ./packages/api	2m 23s
Test Packages / Test ./packages/cache	2m 15s
Test Packages / Test ./packages/hono	1m 51s
Test Packages / Test ./packages/nextjs	2m 59s
Test Packages / Test ./packages/rbac	1m 45s
	1h 23m 4s

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