Tweak help and README #549

Job	Run time
Test with python 3.6 on windows-latest	2m 7s
Test with python 3.7 on windows-latest	1m 22s
Test with python 3.8 on windows-latest	4m 29s
Test with python 3.12 on windows-latest	4m 32s
Test with python 3.6 on macos-latest	58s
Test with python 3.7 on macos-latest	48s
Test with python 3.8 on macos-latest	4m 10s
Test with python 3.12 on macos-latest	4m 21s
Test with python 2.7 on ubuntu-20.04	32s
Test with python 3.6 on ubuntu-20.04	36s
Test with python 3.7 on ubuntu-latest	35s
Test with python 3.8 on ubuntu-latest	3m 22s
Test with python 3.9 on ubuntu-latest	3m 27s
Test with python 3.10 on ubuntu-latest	3m 33s
Test with python 3.11 on ubuntu-latest	3m 21s
Test with python 3.12 on ubuntu-latest	4m 38s
	42m 51s

Provide feedback