Updated Readme.md file for python 3

[thearpitanand]

Updated commands for python 3

[Lunarequest]

Since python 2 has been depreciated since January 1, 2020 most distributions(baring stale ones) have python and python3, I don't see a need for this being explicitly being stated, This are my 2 cents but it seems like sysmon is no longer maintained

for more info on python2 depreciation read:
https://www.python.org/dev/peps/pep-0373/
https://www.python.org/dev/peps/pep-0404/