Add default matrix_postgres_additional_databases

roles/matrix-postgres/defaults/main.yml

@@ -30,3 +30,13 @@ matrix_postgres_container_extra_arguments: []
 #
 # Takes an "<ip>:<port>" or "<port>" value (e.g. "127.0.0.1:5432"), or empty string to not expose.
 matrix_postgres_container_postgres_bind_port: ""
+
+# A list of additional (databases and their credentials) to create.
+#
+# Example:
+# matrix_postgres_additional_databases:
+#   - name: matrix_appservice_discord
+#     pass: some-password
+#   - name: matrix_appservice_slack
+#     pass: some-password
+matrix_postgres_additional_databases: []