feat(docker-compose): Align env example file name with other docs

docker-compose/examples/hashicorpvault/env/fqdn_context.env.example

@@ -0,0 +1,29 @@
+CONTEXT=fsf
+
+
+
+# Set something sensible here and uncomment
+# ---
+# VAULT_VERSION=x.y.z
+
+
+
+# A ${LOCATION} var is usually not needed. It may be helpful when a ${CONTEXT}
+# extends over more than one location e.g. to bind-mount location-specific
+# config files or certificates into a container.
+# ---
+# LOCATION=
+
+
+
+# Feel free to leave defaults. They apply while these vars are commented out
+# ---
+# RESTARTPOLICY=unless-stopped
+# TIMEZONE=Etc/UTC
+
+
+
+# See 'docker-compose.override.yml' for how to make a variable available in
+# a Dockerfile
+# ---
+# EXAMPLE_ARG_FROM_ENV_FILE=must_be_available_in_dockerfile