Remove reference to file that no longer exists (#5360)

Author: mrubens

.roo/rules/rules.md

@@ -21,7 +21,3 @@
     - Use Tailwind CSS classes instead of inline style objects for new markup
     - VSCode CSS variables must be added to webview-ui/src/index.css before using them in Tailwind classes
     - Example: `<div className="text-md text-vscode-descriptionForeground mb-2" />` instead of style objects
-
-# Adding a New Setting
-
-To add a new setting that persists its state, follow the steps in docs/settings.md