Fix spelling

[cbrnr]

Checklist

• [x] Relevant issues have been referenced (there is no issue)
• [x] CHANGELOG.md has been updated (this minor change does not need to be mentioned I think)
• [x] Tests are not relevant

Description I have tried to improve the README.md by (1) starting Python with an uppercase P, (2) using PEP8-style comments (two spaces before the #), and (3) some other minor things.

I hope this is useful because I think it improves readability. You also might want to capitalize Python in the GitHub repository "About" text.

Thanks for this great extension!

[kbrose]

Thanks for going through and cleaning things up a bit @cbrnr, I appreciate it. My only ask is that you revert the additional spaces before # in comments -- I know it's the PEP8 way but in this README I personally find it easier to read with just one space between the pipe character and the comment character.

[cbrnr]

Done @kbrose!