examples: remove with-tailwindcss example

[JamBalaya56562]

What?

1. Remove with-tailwindcss example
2. Remove the lines refer to with-tailwindcss example.

Why?

At #46927, The most of files was removed from with-tailwindcss example because a --tailwind flag was introduced to the create-next-app CLI.
The README.md in this example just shows how to use a --tailwind flag, so it's no longer needed.

Improving Documentation

• Run pnpm prettier-fix to fix formatting issues before opening the PR.
• Read the Docs Contribution Guide to ensure your contribution follows the docs guidelines: https://nextjs.org/docs/community/contribution-guide

Adding or Updating Examples

• The "examples guidelines" are followed from our contributing doc https://github.com/vercel/next.js/blob/canary/contributing/examples/adding-examples.md
• Make sure the linting passes by running pnpm build && pnpm lint. See https://github.com/vercel/next.js/blob/canary/contributing/repository/linting.md

[ijjk]

Allow CI Workflow Run

• approve CI run for commit: 71c5bb3

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