Fixed names (PRCARD to PRWORD) in 'ZXDev/Libs/Basic'.
Fixed typos in 'ZXDev/Mod/HelloWorld' & 'TinyHello'.
Add 'ZXDev/Libs/Platform'.
Add 'ZXDev/Mod/Unsigned' example 'how to work with unsigned numbers in ZXDev/Ofront'.
Update 'Sym/Basic.osf' (fixed name (PRCARD to PRWORD) in 'ZXDev/Libs/Basic').