Add docs

.env.sample

@@ -37,6 +37,7 @@ PENPOT_SMTP_DEFAULT_REPLY_TO=penpot@example.com
 SECRET_DB_PASSWORD_VERSION=v1
 SECRET_SMTP_PASSWORD_VERSION=v1
 
+# e.g. for Keycloak https://id.example.com/auth/realms/example/
 #PENPOT_OIDC_BASE_URI=
 #PENPOT_OIDC_CLIENT_ID=
 #PENPOT_OIDC_CLIENT_SECRET=

README.md

@@ -8,7 +8,7 @@
 * **Backups**: 
 * **Email**: 
 * **Tests**: 
-* **SSO**: 
+* **SSO**: ❶💚 (OAuth)
 <!-- endmetadata -->
 
 ## Basic usage