Delete edge functions examples (#1135)

Edge Functions are being deprecated. We recommend using the full Node.js
runtime with Fluid compute instead. [Learn more
here](https://www.youtube.com/watch?v=G-ngjNfMnvE) or [read the
docs](https://vercel.com/docs/functions/fluid-compute). Functions using
Fluid retain the benefits of Edge Functions, without the downsides of
the limited Edge runtime. Further, most workloads have 1-3 regions for
their data storage, where you should co-locate your compute. Ensure your
Vercel Function region is the same as your database.

Places where these folders were linked (through Vercel templates) have
been updated.

Author: leerob