Move example files to an appropriate directory

[lon-io]

No description provided.

[kirill-konshin]

Can't merge while CI is failing, please fix.

[lon-io]

I tried to point the example directory to next by doing:

"next": "next example",
"next:export": "next export example",
"next:build": "next build example",
"next:start": "next start example",

But it turns out babel-loader won't transpile files from outer directories:
babel/babel-loader#293

So I reverted back to the initial structure with some modifications

[kirill-konshin]

But it turns out babel-loader won't transpile files from outer directories

This was exactly the reason why it was laid out the way it was.

Closing because PR now contain only stylistic changes.