Documentation Suggestion - add a compatibility matrix of OS family, Python version, python-oracledb version

[mikesmithers]

Could a compatibility matrix be included somewhere in the documentation so that it's easy to tell which package version can be used for which OS/Python version - e.g.

Python	Windows	MacOS	Linux
3.6	n/a	n/a	1.4.2
3.7	2.3.0	2.3.0	2.3.0
3.8	3.0.0	3.0.0	3.0.0
3.9	3.4.2	3.4.2	3.4.2