Update oAuth documentation

docs/oauth.md

@@ -1,3 +1,25 @@
 # HEP Oauth settings
 
 https://www.hep-verlag.ch/profile/partner
+
+Login with credentials from 1Password
+
+create new client
+
+name: `'{Name} {Environment}'` e.g. `'MyKV Stage'`
+
+grant: Access Token Grant
+
+redirect url: `https://{app_url}/api/oauth/callback/`
+
+fallback url: 'https://myskillbox.ch/anleitung' (change if another one is available for the server)
+
+Note the Client ID and the Client Secret of the newly created client
+
+Go to the environment on heroku, and enter the following env variables:
+- OAUTH_ACCESS_TOKEN_URL: https://sso.hep-verlag.ch/oauth/token
+- OAUTH_API_BASE_URL: https://cms.hep-verlag.ch
+- OAUTH_AUTHORIZE_URL: https://sso.hep-verlag.ch/oauth/authorize
+- OAUTH_CLIENT_ID: <Client ID>
+- OAUTH_CLIENT_SECRET: <Client Secret>
+- OAUTH_LOCAL_REDIRECT_URI: https://<App URL>/api/oauth/callback/