Update README.md

host/convex/docker/env.example

@@ -0,0 +1,17 @@
+BACKEND_CONTAINER_NAME=
+DASHBOARD_CONTAINER_NAME=
+INSTANCE_NAME=
+CONVEX_CLOUD_ORIGIN=
+CONVEX_SITE_ORIGIN=
+DISABLE_BEACON=
+REDACT_LOGS_TO_CLIENT=
+DO_NOT_REQUIRE_SSL=
+NEXT_PUBLIC_DEPLOYMENT_URL=
+#POSTGRES_URL=
+#DATABASE_URL=
+#INSTANCE_SECRET=
+#CONVEX_RELEASE_VERSION_DEV=
+#ACTIONS_USER_TIMEOUT_SECS=
+#MYSQL_URL=
+#RUST_LOG=
+#RUST_BACKTRACE=