Added Shells of menu items for File (new, open, save, saveAs, and exit)
as well as for View (set Default window size), and Help (about and about
Qt).

Signed-off-by: Corbin Weidner <cweidner3+git@gmail.com>
Added a shell to the basics page for the DnD character. Also added it to
the MainWindow in a tab as an example for future tabs.

Signed-off-by: Corbin Weidner <cweidner3+git@gmail.com>