feat(docker-compose): Allow directory name different from service or component names

docker-compose/examples/hashicorpvault/build-context/Dockerfile

@@ -4,10 +4,10 @@
 # ARG EXAMPLE_ARG_FOR_DOCKERFILE
 
 # Another env var, this one's needed in the example build step below:
-# ARG HASHICORPVAULT_VERSION
+# ARG VAULT_VERSION
 
 # Example
-# FROM "hashicorpvault:${HASHICORPVAULT_VERSION}"
+# FROM "vault:${VAULT_VERSION}"
 # RUN apt-get update && \
 #     apt-get -y install \
 #     somepackage-6.q16-6-extra && \