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Add comprehensive README with preserved version note #27

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Run time

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Job	Run time
Test JDK 21, ubuntu-latest	36s
Test JDK 8, macOS-14	44s
Test JDK 8, ubuntu-latest	30s
Test JDK 11, macOS-14	27s
Test JDK 11, ubuntu-latest	34s
Test JDK 21, macOS-14	35s
	3m 26s