Doc: Add link to Qt WebChannel and Qt WebKit examples page.

-more exposure to those modules is needed.

Change-Id: I0e52cd320084e4376bc280d27282502835cb6df5
Reviewed-by: Venugopal Shivashankar <venugopal.shivashankar@digia.com>
Reviewed-by: Martin Smith <martin.smith@digia.com>