Documentation on how to set passwords.

[sakoht]

This library is great, and seems to be a full replacement for the standard Apache http auth. However it is impossible to actually use if someone doesn't know how to set passwords. I think people are left doing what I am doing: scratching my head and reading the source code, guessing, and failing repeatedly.

Ultimately this needs a simple extension to the README that:

• enumerates the ways that a password can be set
• shows one example of using each

Ideally one example shows how to just make it read a standard .htaccess file and have it just work. Everything else is a corner case.

If I figure this out, I'll make a PR.

[sakoht]

This overlaps #56 asking about how to do this with BasicAuth.