Update oauth.mdx (#860)

Added better clarification for point number 5 based on a conversation I
had earlier and struggled to follow this doc.

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

docs/integrations/github/oauth.mdx

@@ -10,7 +10,7 @@ description: Authenticate users via GitHub OAuth
 2.  Set the Authorization callback URL to `https://idp.ngrok.com/oauth2/callback`.
 3.  Submit the form. A working example registration: ![](/img/howto/oauth/1-github-register.png)
 4.  Save the client ID and client secret from the application overview: ![](/img/howto/oauth/2-github-client_id_and_secret.png)
-5.  Return to the ngrok dashboard and create or edit an OAuth endpoint configuration module.
+5.  Return to the ngrok dashboard and create or edit an OAuth endpoint configuration module. You do this by [going to your edges](https://dashboard.ngrok.com/cloud-edge/edges), clicking on the edge that you want to apply OAuth to, and selecting the OAuth tab within edge your routes. From there you will be prompted to begin setup.
 6.  Choose to use your own application with GitHub as the provider.
 7.  Include the client ID and secret from earlier.
 8.  Add any scopes your application requires.