Bug 665833: Added Mallard help for GNOME-robots

Added:
appearance.page, basics.page, controls-change,
controls-default.page, game-types.page, index.page,
moves.page, scores.page
Add icon next to title; fix typo; clarify possible moves

See first three items of
https://bugzilla.gnome.org/show_bug.cgi?id=665833#c3
help: install Robots logo
help: do not name the page "Robots logo Robots"

This is displaying incorrectly in Yelp's window title and in the
dropdown menu.
Update documentor credits

https://bugzilla.gnome.org/show_bug.cgi?id=665833