update doc/*/scripting/builtins/libfile.md

doc/en/scripting/builtins/libfile.md

@@ -133,6 +133,12 @@ file.unmount(entry_point: str) --> str
 
 Unmounts the entry point.
 
+```lua
+file.create_zip(directory: str, output_file: str) --> str
+```
+
+Creates a ZIP archive from the contents of the specified directory.
+
 ```lua
 file.name(path: str) --> str
 ```