Add vercel support - update to nextjs 12

[Toumash]

Adds vercel support.

Current state
This app wont deploy to vercel.com
Desired state
This app will easily deploy to vercel.com

The problem
The problem was probably caused by vercel not supporting older versions of nextjs - im no sure.
Whatever, the build was not passing anyway, and after my changes - it does pass.

Error from vercel deployment

Export successful. Files written to /vercel/path0/out
--
21:14:52.682 | Done in 37.26s.
21:14:52.693 | Error: The file "/vercel/path0/.next/routes-manifest.json" couldn't be found. This is normally caused by a misconfiguration in your project.
21:14:52.693 | Please check the following, and reach out to support if you cannot resolve the problem:
21:14:52.693 | 1. If present, be sure your `build` script in "package.json" calls `next build`.  2. Navigate to your project's settings in the Vercel dashboard, and verify that the "Build Command" is not overridden, or that it calls `next build`.  3. Navigate to your project's settings in the Vercel dashboard, and verify that the "Output Directory" is not overridden. Note that `next export` does **not** require you change this setting, even if you customize the `next export` output directory. Learn More: https://err.sh/vercel/vercel/now-next-routes-manifest

[Toumash]

The netlify build is failling, because it runs on older version of node

error next@12.1.0: The engine "node" is incompatible with this module. Expected version ">=12.22.0". Got "12.18.0"