Combobox: show example with a prefilled value and how to suspend filtering

[ianmcburnie]

When a combobox renders with a prefilled value, all of the other suggestions in the list will be filtered out by default. An application developer could temporarily set autocomplete from list to none to increase awareness that there is more than one suggestion. As soon as an input event is received, the filtering would become activate (i.e set from none to list).

Create a new example showing this in action.