Added back the original section 'Using Docker Image'

Dev Container section separated from Docker Image section

README.md

@@ -103,11 +103,16 @@ Rather than creating your own local dev environment, GitPod provides a ready to
 
 #### Using Dev Container
 
-You can also build a [Dev Container](https://containers.dev/) - basically a docker container - suitable
-for building and testing Selenium using the devcontainer.json in the
+As an alternative you can build a [Dev Container](https://containers.dev/) - basically a docker container -
+suitable for building and testing Selenium using the devcontainer.json in the
 [.devcontainer](.devcontainer/devcontainer.json) directory. Supporting IDEs like VS Code or IntelliJ IDEA
 should point you to how such a container can be created.
 
+#### Using Docker Image
+
+You can also build a Docker image suitable
+for building and testing Selenium using the Dockerfile in the
+[dev image](scripts/dev-image/Dockerfile) directory.
 
 ## Building