Basic usage for DEFAULT_REGISTRIES and READ_ONLY_REGISTRIES.

Behaviors:

• DEFAULT_REGISTRIES:
  • will set the list of registries in the localstorage when the localstorage is empty.
  • will overwrite the list of registries every time when READ_ONLY_REGISTRIES=true
• READ_ONLY_REGISTRIES:
  • will remove dialog for Add and Remove registries

These options works only when SINGLE_REGISTRY=false

See #219