Remove mention of email address in user()

I was trying to use the `user()` method yesterday w/ an email address to no avail. When I talked to cade on IRC, he said he had to change the method to not support email addresses, so I'm updating the docs now.
Minor markdown formatting fix in README.md
Merge pull request #21 from toolness/patch-1

Remove mention of email address in user()
Merge pull request #22 from toolness/patch-2

Minor markdown formatting fix in README.md
Bug 951761 - remixCount function and documentation
0.5.14
Add remixurl and editurl to wrapped makes
0.5.15
Bug 914290 - Autocomplete tag route support
0.5.16
Bug 922166 - protected search used when Hawk credentials supplied
0.5.17
Fix bug 964067 - Add 10s timeout for MakeAPI requests
0.5.18
Bug 987898 - Refactor MakeAPI Client with prototypes and better data encapsulation
0.5.19
Bug 988544 - fix wrapped make functions
0.5.20
0.5.21
bug 998096 - add support for toggling remix count hydration