Update introduction.md (#41226)
Update introduction.md (#41226)

Fixed link to phases lines in the documentation



## Documentation / Examples

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


Co-authored-by: JJ Kasper <fbae0e752deb2c0fed663fa6dec6c97ee2546cfe@users.noreply.github.com>
JeromeFitz/next.js,JeromeFitz/next.js,JeromeFitz/next.js,JeromeFitz/next.js