examples: introduce LaunchPad in strapi (#73244)

## Description

The previous
[nextjs-corporate-starter](https://github.com/strapi/nextjs-corporate-starter)
has been archived.
With the release of Strapi 5, launched an even more awesome demo/starter
project called [LaunchPad](https://github.com/strapi/LaunchPad).

You can learn more about the LaunchPad app from [the
blog](https://strapi.io/blog/launchpad-demo-app).

In addition, update
[.gitignore](https://github.com/vercel/next.js/blob/canary/examples/cms-strapi/.gitignore).

CC: @samcx 

### Adding or Updating Examples

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

Co-authored-by: Sam Ko <sam@vercel.com>

examples/cms-strapi/.gitignore

@@ -3,8 +3,12 @@
 # dependencies
 /node_modules
 /.pnp
-.pnp.js
-.yarn/install-state.gz
+.pnp.*
+.yarn/*
+!.yarn/patches
+!.yarn/plugins
+!.yarn/releases
+!.yarn/versions
 
 # testing
 /coverage
@@ -24,9 +28,10 @@
 npm-debug.log*
 yarn-debug.log*
 yarn-error.log*
+.pnpm-debug.log*
 
-# local env files
-.env*.local
+# env files (can opt-in for committing if needed)
+.env*
 
 # vercel
 .vercel

examples/cms-strapi/README.md

@@ -1,3 +1,3 @@
-## Deprecated
+# Strapi Example
 
-The Strapi CMS example is deprecated. Please check out [Strapi’s official demo application](https://github.com/strapi/nextjs-corporate-starter).
+The official example [LaunchPad](https://github.com/strapi/LaunchPad) for using [Strapi](https://strapi.io/) is available.