The comments refer to the original code that was setting a declarative
source property in the Component.onCompleted signal handler, but this
does not really apply anymore now that we have an imperative method to
load document contents.
Change-Id: I9054cbc6ecec2c66d65251c49a5b1de2ad0623dc
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>