add docker specific instructions back to readme

Signed-off-by: nikki everett <[email protected]>

basic-template-dockerfile/{{cookiecutter.project_name}}/README.md

@@ -7,5 +7,19 @@ A template for the recommended layout of a Flyte enabled repository for code wri
 To get up and running with your Flyte project, we recommend following the
 [Flyte getting started guide](https://docs.flyte.org/en/latest/getting_started.html).
 
+This project includes a script `docker_build.sh` that you can use to build a
+Docker image for your Flyte project.
+
+```
+# help
+./docker_build.sh -h
+
+# build an image with defaults
+./docker_build.sh
+
+# build an image with custom values
+./docker_build.sh -p {{ cookiecutter.project_name }} -r <REGISTRY> -v <VERSION>
+```
+
 We recommend using a git repository to version this project, so that you can
 use the git sha to version your Flyte workflows.