Update hooks.md

guide/hooks.md

@@ -8,6 +8,7 @@ With Fiber v2.30.0, you can execute custom user functions when to run some metho
 - [OnListen](#onlisten)
 - [OnFork](#onfork)
 - [OnShutdown](#onshutdown)
+- [OnMount](#onmount)
 
 ## Constants
 ```go
@@ -193,4 +194,4 @@ func main() {
 
 {% hint style="warning" %}
 OnName/OnRoute/OnGroup/OnGroupName hooks are mount-sensitive. If you use one of these routes on sub app and you mount it; paths of routes and groups will start with mount prefix.
-{% endhint %}
+{% endhint %}