Added "Converting types"

[guettli]

No description provided.

[coveralls]

Coverage remained the same at 88.309% when pulling 2144ee7 on guettli:patch-1 into 26ff5b7 on theskumar:master.

[sergeyklay]

@bbc2 Could you please take a look? Can we have this in the docs?

[bbc2]

Thank you for the suggestion but I don't think it's worth having this in the readme because the fact that os.getenv returns a string is already documented: https://docs.python.org/3.9/library/os.html#os.getenv. Python-dotenv doesn't change that.

[ramwin]

I like this commit. If this was merge into main branch, It really saves newbie a lot of time. And since it only add some suggestions to the README.md file, It didn't break the package's behaviour.

[alexeyshockov]

Yeah, such examples would be definitely appreciated. IMO there are no reasons to not mention some existing env vars technics.