feat(oidc_user_backend): add ansible role

roles/oidc_user_backend/README.md

@@ -0,0 +1,26 @@
+# `finallycoffee.nextcloud.oidc_user_backend` ansible role
+
+Configure OIDC user backends in nextcloud using this ansible role.
+This role can be run multiple times with different arguments in order to
+configure multiple oidc-based user backends.
+
+## Configuration
+
+Set `oidc_user_backend_provider_identifier` to a unique identifier.
+Populate your provider information in the `oidc_user_backend_config_provider_provider_(settings_)`
+like this:
+
+```yaml
+oidc_user_backend_config_provider_identifier: my_provider
+oidc_user_backend_config_provider_discovery_endpoint: https://idp.example.com/
+oidc_user_backend_config_provider_client_id: my-client-id
+oidc_user_backend_config_provider_client_secret: my-client-secret
+
+# All options to the occ command are avaible in the
+# `oidc_user_backend_config_provider_settings_` namespace
+oidc_user_backend_config_provider_settings_unique_id: true
+oidc_user_backend_config_provider_settings_send_id_token_hint: true
+oidc_user_backend_config_provider_settings_mapping_display_name: name
+oidc_user_backend_config_provider_settings_mapping_uid: preferred_username
+oidc_user_backend_config_provider_settings_mapping_email: email
+```