Another folder reorganisation

[elstoc]

The various components are pretty isolated from one another, and all use code that's strongly linked but scattered all over the site. Perhaps a general structure change is called for, whereby the top level of the src folder contains a folder per component set, so...

src
  auth
  gallery
  markdown
  shared
  site
  videodb

Beneath each of these are various optional subfolders, for example:

src
  auth
    api (including functions to all endpoints, along with api data types)
    components
    hooks

Perhaps finally also a top-level utils directory

[elstoc]

done