Represents a doclink in a rich text item.
Access
To access a RichTextDoclink object,
use the RichTextNavigator methods in conjunction with the type RTELEM_TYPE_DOCLINK.
Usage
Hotspot text representing a doclink can
be retrieved by navigating to the doclink, enclosing it in a RichTextRange,
and retrieving the associated text with TextRun. If the doclink is
not a hotspot, no text is present.