docs: remove JSX comment from content in dashboard (#16156)

Author: paulpopus

docs/custom-components/dashboard.mdx

@@ -176,8 +176,6 @@ If you don't define a `defaultLayout`, the collections widget will be automatica
 
 ### User Customization
 
-{/* TODO: maybe a good GIF here? */}
-
 Users can customize their dashboard by:
 
 1. Clicking the dashboard dropdown in the breadcrumb