Update README.md

Signed-off-by: John Lago <[email protected]>

Author: Lagoja

README.md

@@ -12,7 +12,7 @@ This repository includes plugins for configuring packages using Devbox.
 Each subfolder contains a plugin for a specific package. To use a plugin, add the following reference to the `include` section of your `devbox.json` file.
 
 ```json
-"includes": [
+"include": [
     "github:jetpack-io/devbox-plugins?dir=<plugin-name>"
 ],
 ```