Clarify username and password in API authentication

Updated the authentication section to clarify username and password details.

Author: mscoutermarsh

getting-started/using-the-api.md

@@ -24,7 +24,7 @@ Generate images from HTML and CSS.
 ## Authentication
 The API uses [HTTP Basic authentication](https://en.wikipedia.org/wiki/Basic_access_authentication). 
 
-- Your username is your **User ID** and your password is your **API Key**. Both of these are available from the [dashboard](https://htmlcsstoimage.com/dashboard). The code samples demonstrate how to authenticate your request.
+- Your username is the **ID** and your password is your **API Key**. Both of these are available from the [dashboard](https://htmlcsstoimage.com/dashboard/api-keys). The code samples demonstrate how to authenticate your request.
 - Treat your API Key like a password. If exposed, it could be used to create images using your account.
 
 ## Creating an image