update deploy README.md to show local deployment examples

deploy/README.md

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+# Deployments
+Deployment of this application uses [Github Deployment Environments](https://docs.github.com/en/actions/deployment/targeting-different-environments/using-environments-for-deployment).
+
+A successful deployment relies on the correct variables being defined in order to deploy to the correct AWS account etc.
+
+### Managing Environments
+You can view the current environment settings by visiting https://github.com/aodn/sample-django-app/settings/environments.
+
+You can view the currently defined variables there or from the cli using:
+```bash
+gh variable list -R aodn/sample-django-app -e staging
+```
+
+### Updating Variables
+Manually updating vars can be tedious and error-prone. Instead, you may define the variables you need as a .env file and push these values:
+```bash
+gh variable set -R aodn/sample-django-app -e staging -f staging.env
+```
+
+### Deploying Locally
+The Terragrunt module for this application depends on variables being present and will fail if they are not.
+
+To test locally, you may want to populate these into your local environment using the following command:
+```bash
+set -a; source ./github/staging.env; set +a
+terragrunt plan
+terragrunt apply
+```
+
+### Using Docker
+A Dockerfile is provided to simplify local deployment, removing the need to install the required binaries on the local system.
+
+N.B. The Dockerfile does assume a valid AWS CLI configuration.
+
+### Example deployment
+Modify the environment variables in `dev.env`:
+```text
+ALB_PARAMETER_NAME=shared-alb-dev-sydney
+APP_NAME=sample-django-app-mybranch
+AWS_ACCOUNT_ID=123456789012
+AWS_REGION=ap-southeast-2
+ECR_PARAMETER_NAME=api
+ECR_REGISTRY=123456789012.dkr.ecr.ap-southeast-2.amazonaws.com
+ECR_REPOSITORY=api
+ENVIRONMENT=mydev-stack
+RDS_PARAMETER_NAME=db01/primary/development
+
+```
+
+```bash
+cd deploy
+docker-compose -f docker-compose.yml run terragrunt
+```
+
+On the container run the following:
+```bash
+set -a; source ./github/dev.env; set +a
+terragrunt plan -out=tf.plan
+terragrunt apply -auto-approve tf.plan
+
+```