update

Author: neilpang

.github/tpl/README.tpl.md

@@ -123,7 +123,7 @@ The code is shared from the host to the VM via `rsync` by default, you can choos
 You can also set `sync: no`, so the files will not be synced to the  VM.
 
 
-When using `rsync` or `scp`,  you can define `copyback: false` to not copy files back from the VM in to the host.
+When using a copy based sync method (`rsync`, `scp`, `tar` or `9p`), you can define `copyback: false` to not copy files back from the VM to the host. It has no effect on `sshfs` and `nfs`, which are live mounts and never copy back.
 
 
 ```yaml