next.js

17da2ca1 - docs: Move general info about next.config.* to its index page (#53542)

docs: Move general info about next.config.* to its index page (#53542) I was reading through the current https://nextjs.org/docs/app/api-reference/next-config-js/pageExtensions and noticed it started explaining different file formats for the `next.config.*` file. Is that information better suited for the https://nextjs.org/docs/app/api-reference/next-config-js index page? There was also a little redundancy at the top. Co-authored-by: Lee Robinson <9113740+leerob@users.noreply.github.com>