add override dir

override/openproject.example.env

@@ -0,0 +1,20 @@
+##
+# All environment variables defined here will only apply if you pass them
+# to the OpenProject container in docker-compose.yml under x-op-app -> environment.
+# For the examples here this is already the case.
+#
+# Please refer to our documentation to see all possible variables:
+#   https://www.openproject.org/docs/installation-and-operations/configuration/environment/
+#
+OPENPROJECT_DOMAIN=
+OPENPROJECT_TAG=
+OPENPROJECT_HTTPS=
+OPENPROJECT_HOST__NAME=
+OPENPROJECT_PORT=
+OPENPROJECT_IMAP_ENABLED=
+OPENPROJECT_DB_USER=
+OPENPROJECT_DB_PASSWORD=
+OPENPROJECT_DB_NAME=
+OPENPROJECT_RAILS_MIN_THREADS=
+OPENPROJECT_RAILS_MAX_THREADS=
+OPENPROJECT_OPDATA=