Creates Postcode lookup field and button when called on
First argument context
is a query selector string which designates where on the DOM the plugin will be instantiated
Second argument config
allows for advanced configuration of the plugin
When invoked, an instance of the Postcode Lookup controller is stored in contollers
Returns an instance of Postcode Lookup controller unless checkKey: true
. If key checking is enabled, controller can be accessed by the onLoaded
callback
Caches all instances of the plugin created via
setup