Examples - Updated with-windcss example for App Router

[archanaagivale30]

This PR updates the with-windcss example to use the App Router. Here are the changes that have been made:

• Renamed the "pages" folder to "app" folder.
• Updated the file index.tsx to page.tsx to align with App Router
• Added the layout.tsx file as part of the App Router.
• removed tag
• updated package versions

cc @samcx

[ijjk]

Allow CI Workflow Run

• approve CI run for commit: bda512a

Note: this should only be enabled once the PR is ready to go and can only be enabled by a maintainer

[socket-security]

New and removed dependencies detected. Learn more about Socket for GitHub ↗︎

Package	New capabilities	Transitives	Size	Publisher
npm/windicss-webpack-plugin@1.8.0	environment, unsafe Transitive: filesystem	+5	325 kB	harlan_zw

🚮 Removed packages: npm/windicss-webpack-plugin@1.6.7), npm/windicss@3.5.1)

View full report↗︎

[samcx]