Add a few more README things on Docker

Makefile

@@ -1,6 +1,5 @@
 DOCKER_COMPOSE = COMPOSE_DOCKER_CLI_BUILD=1 DOCKER_BUILDKIT=1 docker compose
 DOCKER_RUN = ${DOCKER_COMPOSE} run -u `id -u`
-DOCKER_CONTAINER_NAME = backend
 MANAGE_EXEC = python /app/src/manage.py
 MANAGE_COMMAND = ${DOCKER_RUN} app ${MANAGE_EXEC}
 
@@ -28,5 +27,5 @@ shell:
 manage_command:
 	${MANAGE_COMMAND} ${ARGS}
 
-build_dev_docker_image:
-	${DOCKER_COMPOSE} build ${DOCKER_CONTAINER_NAME}
+build:
+	${DOCKER_COMPOSE} build

README.md

@@ -40,6 +40,19 @@ Working with the Docker Compose setup is made easy with the `Makefile` provided
     make run
     ```
 
+#### Building and running other things
+
+```bash
+# Build the containers
+make build
+
+# Create a superuser
+make createsuperuser
+
+# Create Django migrations (after this, maybe you need to change file permissions in volume)
+make makemigrations
+```
+
 ### Using hatch
 
 #### Requirements