13 more mower manuals added

Links to 13 more lawn mower manuals and parts lists were added recently, for the following brands:

- American Lawn Mower Company: 1 mower manual

- Craftsman: 1 mower manual

- Hyundai: 3 mower manuals

- MEP: 1 mower parts list

- PowerSmart: 1 mower manual

- RedMax: 1 mower manual, 2 mower parts lists

- Ryobi: 2 mower manuals

- Scag: 1 mower parts list (and 1 broken link updated)