"First 3 examples" should not have ambiguous types

[jpmckinney]

From open-contracting/cove-oc4ids#20

If the value is a string, it should be surrounded by quotation marks. This makes it easier to see that e.g. 500 is "500" instead of 500. It also means something will be printed to the screen for the empty string ("" instead of nothing).

Moved from OpenDataServices/cove#1198