Update docs/en/user_guide/advanced/custom_server_mock.md

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: thelooter

docs/en/user_guide/advanced/custom_server_mock.md

@@ -16,7 +16,7 @@ class. This could be if you want to implement some of the unimplemented methods
 or simply provide your own mocks for certain methods.
 
 To do that you can simply pass your custom mock that extends `ServerMock` to the
-`MockBukkit.mock(ServerNock)` method.
+`MockBukkit.mock(ServerMock)` method.
 
 ::: code-group