add comments for docker-compose download in centos 7

compose.yaml

@@ -1,4 +1,11 @@
-# github: https://github.com/filesite-io/machete
+# source code: https://github.com/filesite-io/machete
+# docker-compose download in linux: https://github.com/docker/compose/releases
+# example for centos 7.*:
+# ```
+# wget "https://github.com/docker/compose/releases/download/v2.32.2/docker-compose-linux-x86_64"
+# chmod +x docker-compose-linux-x86_64
+# ./docker-compose-linux-x86_64 --help
+# ```
 name: filesite_machete
 services:
     web: