One-time PR for Doc Reviews

@croche-okta @wdawson-okta @srinivasanagandla-okta @stsai-okta @lboyette-okta @hoanguyen-okta @karlmcguinness-okta @cwu-okta @tthompson-okta @eklein-okta

Hi team,

Since the material has been pushed to master, this pull request is a little unusual. Please add any comments to the docs here by the end of the day Monday, September 29, 2014. I will make changes and create a new branch and a new PR for the changes. Then, I will discard this PR. 

Please ping me if this doesn't work for you.

Thanks,
Evan
Also the main use case of the factors API is to manage the User's factors profile like reset, enroll factors.