Add Docker tips to README.

lmwnshn · lmwnshn · commit cb96586b2fce · 2021-08-24T13:33:14.000-04:00
diff --git a/cmudb/env/README.md b/cmudb/env/README.md
@@ -1 +1,17 @@
 The `env` folder is for all files that relate to setting up a development or CI environment.
+
+# Docker tips.
+
+```
+# Build a Docker image named pgnp from our Dockerfile.
+docker build --tag pgnp --file ./cmudb/env/Dockerfile .
+
+# Run the Docker image in the pgnp_instance container.
+docker run --detach --interactive --tty --name pgnp_instance pgnp
+
+# Connect to the Docker container pgnp_instance.
+docker exec --interactive --tty pgnp_instance /bin/bash
+
+# Shut down the container AND DELETE ALL THE DATA ON IT.
+docker container rm --force --volumes pgnp_instance
+```
