Update plug link (#26)

rands0n · web-flow · commit e9a3b1c4bb11 · 2021-09-05T14:40:35.000+02:00
diff --git a/README.md b/README.md
@@ -15,7 +15,7 @@ def deps do
 end
 ```
 
-If you're using [Plug][plug], you can already use the functionality in plug_crypto since Plug depends on it.
+If you're using [Plug](https://github.com/elixir-plug/plug), you can already use the functionality in plug_crypto since Plug depends on it.
 
 ## Contributing
 
