docs: Update codegen configuration documentation #1434

Job	Run time
changes	4s
Cocoapods Integration Tests - macOS	11s
Codegen Test Configurations - macOS	6m 37s
Run swift build for SPM packages (apollo-ios)	23s
Run swift build for SPM packages (apollo-ios-codegen)	27s
Run swift build for SPM packages (apollo-ios-pagination)	39s
Run Tuist Generation	3m 13s
Verify CLI Binary Archive - macOS	6s
Verify Frontend Bundle Latest - macOS	11s
Apollo Unit Tests - macOS	11s
Apollo Integration Tests - macOS	0s
Codegen CLI Unit Tests - macOS	3m 10s
Codegen Lib Unit Tests - macOS	3m 36s
ApolloPagination Unit Tests - macOS	9s
	18m 57s

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