Updated Adding a non keyboard device yourself (markdown)

Adding-a-non-keyboard-device-yourself.md

@@ -43,7 +43,7 @@ namespace Artemis.DeviceProviders.MyDevice
 ```
 
 ### Step 4
-Implement the methods. You can do this however you like, just keep in mind that UpdateDevice is called 25 times a second, or ever 40 ms, so make sure it's quick.
+Implement the methods. You can do this however you like, just keep in mind that UpdateDevice is called 25 times a second, or every 40 ms, so make sure it's quick.
 
 A super simple untested example using a serial port to talk to an Arduino:
 ```cs