improve wording as per review notes

docs/proxy.md

@@ -19,7 +19,7 @@ Once traffic is routed to the proxy, you will need to install the proxy's CA cer
 ## Demonstration
 Envbuilder clones a repository that contains your `devcontainer.json` and optional `Dockerfile` so that it can build your container. If the clone is done using HTTPS, then TLS verification must succeed or be disabled. If a transparent HTTPS proxy is present, TLS verification will fail unless Envbuilder trusts the proxy’s certificate. Therefore, we need to configure Envbuilder to trust your proxy. 
 
-The summary in the previous section shows how to configure Envbuilder using Terraform for Docker and Kubernetes. For this example we'll use docker directly to avoid complexity that might result in confusion. Docker is also more likely than Terraform to already be installed in your testing environment.
+For this example we'll use docker, but the configuration is applied using environment variables that can be set analogously in Kubernetes or elsewhere.
 
 Before we introduce an HTTPS proxy, let's prove that envbuilder runs normally. Run the following docker command to obtain a shell within an Envbuilder built environment:
 ```bash