Updated Using ' pre hook', ' post hook', ' renew hook' and ' reload cmd' (markdown)

Using-'--pre-hook',-'--post-hook',-'--renew-hook'-and-'--reload-cmd'.md

@@ -3,5 +3,6 @@ Those hooks are only work with `--issue` or `--install-cert` command.
 ```sh
 acme.sh --install-cert -d example.com  \
         --pre-hook "echo this is pre hook"  \
-        --post-hook "echo this is post hook."  .......
+        --post-hook "echo this is post hook."  \
+        --renew-hook "echo this will be called when success renewed."  .......
 ```