Update README with updated Elgato protocol documentation link.

Author: abcminiuser

README.md

@@ -8,7 +8,7 @@ without the official software. This can allow you to create your own custom
 front-ends, such as a custom control front-end for home automation software.
 
 Protocol documentation for various StreamDeck products are
-[published the Elgato website](https://docs.elgato.com/streamdeck).
+[published the Elgato website](https://docs.elgato.com/streamdeck/hid/).
 
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