Clarify access token refresh

Author: bbiggerr

openapi.yaml

@@ -126,14 +126,14 @@ info:
     Authorization: Bearer 03d084436a6c91fbafd5c4b20c82e5056a2e9ce1635920c30dc8d81dc7a6665c
     ```
 
-    To refresh access, make another request with the following parameters int he POST body:
+    This `access_token` is set to expire in two hours. To refresh access prior to expiration, make another request to the same URL with the following parameters in the POST body:
 
     | PARAMETER | DESCRIPTION |
     |-----------|-------------|
     | grant_type | The grant type you're using. Use "refresh_token" when refreshing access. |
     | client_id | Your app's client ID. |
     | client_secret | Your app's client secret. |
-    | refresh_token | The `refresh_token` received from the previous response |
+    | refresh_token | The `refresh_token` received from the previous response. |
 
     You'll get another response with an updated `access_token` and `refresh_token`, which can then be used to refresh access again.