Add custom image build to readme

README.md

@@ -81,6 +81,21 @@ f"SITE_ADMIN_PASS={admin_pass}\n",
 
 from inside the frappe-docker repo:
 
+<!-- Setup reference to our own repo -->
+
+`APPS_JSON_BASE64=$(echo ${APPS_JSON} | base64 -w 0)`
+
+<!-- build the docker image -->
+
+`sudo docker build \
+  --build-arg=FRAPPE_PATH=https://github.com/frappe/frappe \
+  --build-arg=FRAPPE_BRANCH=version-15 \
+  --build-arg=PYTHON_VERSION=3.11.6 \
+  --build-arg=NODE_VERSION=18.18.2 \
+  --build-arg=APPS_JSON_BASE64=$APPS_JSON_BASE64 \
+  --tag=local-frappe \
+  --file=images/custom/Containerfile .`
+
 `sudo python3 easy-installer.py --prod --email support@lasthourhosting.org --site erp.sprinklersnorthwest.com`
 `sudo docker compose -p frappe exec backend bench use erp.sprinklersnorthwest.com`