📝 minor docs copy edit - add two words

[ci skip]

docs/api/ipc-main.md

@@ -16,8 +16,8 @@ It is also possible to send messages from the main process to the renderer
 process, see [webContents.send][web-contents-send] for more information.
 
 * When sending a message, the event name is the `channel`.
-* To reply a synchronous message, you need to set `event.returnValue`.
-* To send an asynchronous back to the sender, you can use
+* To reply to a synchronous message, you need to set `event.returnValue`.
+* To send an asynchronous message back to the sender, you can use
   `event.sender.send(...)`.
 
 An example of sending and handling messages between the render and main