Link to the SMART app launch specification in the description of appContext (#383)

Fixes #311 and fixes #265

Author: isaacvetter

docs/specification/1.0.md

@@ -405,7 +405,7 @@ Field | Optionality | Type | Description
 <nobr>`label`</nobr>| REQUIRED | *string* | Human-readable label to display for this link (e.g. the EHR might render this as the underlined text of a clickable link).
 `url` | REQUIRED | *URL* | URL to load (via `GET`, in a browser context) when a user clicks on this link. Note that this may be a "deep link" with context embedded in path segments, query parameters, or a hash.
 `type` | REQUIRED | *string* | The type of the given URL. There are two possible values for this field. A type of `absolute` indicates that the URL is absolute and should be treated as-is. A type of `smart` indicates that the URL is a SMART app launch URL and the EHR should ensure the SMART app launch URL is populated with the appropriate SMART launch parameters.
-`appContext` | OPTIONAL | *string* |  An optional field that allows the CDS Service to pass context regarding the launch of this SMART app from the CDS card to the SMART app. The `appContext` field should only be valued if the link type is `smart` and is not valid for `absolute` links. The `appContext` field and value will be sent to the SMART app as part of the [OAuth 2.0][OAuth 2.0] access token response, alongside the other launch context when the SMART app is launched.
+`appContext` | OPTIONAL | *string* |  An optional field that allows the CDS Service to pass context regarding the launch of this SMART app from the CDS card to the SMART app. The `appContext` field should only be valued if the link type is `smart` and is not valid for `absolute` links. The `appContext` field and value will be sent to the SMART app as part of the [OAuth 2.0][OAuth 2.0] access token response, alongside the other [SMART launch parameters](http://www.hl7.org/fhir/smart-app-launch/scopes-and-launch-context/#launch-context-arrives-with-your-access_token) when the SMART app is launched.
 
 ### Example
 
@@ -589,4 +589,4 @@ As another example, an extension defined on the discovery response could look li
   ]
 }
 ```
-[OAuth 2.0]: https://oauth.net/2/
+[OAuth 2.0]: https://oauth.net/2/