21 tool manuals added

21 more tool manuals and parts lists were added recently:

Craftex:
   - 1 grinder manual
   - 1 nailer manual

Hitachi:
   - 1 air compressor manual
   - 1 cut-off machine parts list
   - 1 drill press manual
   - 1 grinder parts list
   - 1 hammer manual, 1 hammer parts list
   - 4 sander manuals
   - 5 saw manuals

Stihl:
   - 1 cut-off machine manual

Wen:
   - 3 saw manuals