message: Minor corrections to auth README
  Some minors things I found while reading the README :)
diff: @@ -136,7 +136,7 @@ Blockstack Authentication makes extensive use of public key cryptography. As men
  ### Transit private key
  -The transit private is an ephemeral key that is used to encrypt secrets that need to be passed from the Blockstack Browser to the app during the authentication process. It is randomly generate by the app at the beginning of the authentication response. The public key that corresponds to the transit private key is stored in a single element array in the `public_keys` key of the authentication request token. The Blockstack Browser encrypts secret data such as the app private using this public key and sends it back to the app when the user signs in to the app. The transit private key signs the app authentication request.
  +The transit private is an ephemeral key that is used to encrypt secrets that need to be passed from the Blockstack Browser to the app during the authentication process. It is randomly generated by the app at the beginning of the authentication response. The public key that corresponds to the transit private key is stored in a single element array in the `public_keys` key of the authentication request token. The Blockstack Browser encrypts secret data such as the app private key using this public key and sends it back to the app when the user signs in to the app. The transit private key signs the app authentication request.
  ### Blockstack ID Identity address private key
  @@ -152,7 +152,8 @@ The app private key serves three functions.
  * It serves as a cryptographic secret that apps can use to perform other cryptographic functions.
  ## Scopes
  -Scopes define the information and permissions an app requests from the user during authentication. If no `scopes` array is provided to the `redirectToSignIn` or `makeAuthRequest` functions.
  +
  +Scopes define the information and permissions an app requests from the user during authentication. If no `scopes` array is provided to the `redirectToSignIn` or `makeAuthRequest` functions, the following is requested:
  - `store_write` - read and write data to the user's Gaia hub in an app-specific storage bucket
  - `publish_data` - publish data so that other users of the app can discover and interact with the user
  - `email` - requests the user's email if available
  @@ -224,6 +225,7 @@ When an application calls [`redirectToSignIn`](http://blockstack.github.io/block
  The way you can add Blockstack Authentication to you app depends on whether your app is a modern decentralized Blockstack App where code runs client-side without trusted servers or a legacy client-server app where a server is trusted.
  ### Authentication in Client-side apps
  +
  This method is appropriate for decentralized client-side apps where the user's zone of trust - the parts of the app that the user is trusting - begins and ends with the code running on their own computer. In apps like these, any code the app interacts with that's not on their own computer such as external servers does not need to know who she is.
  [Blockstack.js](https://github.com/blockstack/blockstack.js) provides API methods that help you to implement Blockstack Authentication in your client-side app.
  