Two different install instructions on PyPI

[elgehelge]

It is a little confusing that two different install instructions are given on PyPI. One using - and one using _. Will both work? Which is the preferred?

[talpay]

flatten-json is correct, flatten_json exists but seems to be a different package?

[amirziai]

i think pypi is insensitive to _ vs -, but i will fix this in the next release. thanks for pointing it out. i agree that it's needlessly confusing.