source-files: fix typo to record-checksum word description in docs
source-files: fix typo to record-checksum word description in docs

slavapestov/factor,AlexIljin/factor,mrjbq7/factor,bpollack/factor,AlexIljin/factor,mrjbq7/factor,AlexIljin/factor,bjourne/factor,bjourne/factor,tgunr/factor,dch/factor,sarvex/factor-lang,dch/factor,factor/factor,mrjbq7/factor,slavapestov/factor,nicolas-p/factor,slavapestov/factor,nicolas-p/factor,slavapestov/factor,nicolas-p/factor,bpollack/factor,dch/factor,factor/factor,bpollack/factor,sarvex/factor-lang,factor/factor,nicolas-p/factor,sarvex/factor-lang,bpollack/factor,tgunr/factor,dch/factor,mrjbq7/factor,bpollack/factor,AlexIljin/factor,nicolas-p/factor,nicolas-p/factor,slavapestov/factor,tgunr/factor,dch/factor,bjourne/factor,bjourne/factor,AlexIljin/factor,factor/factor,dch/factor,sarvex/factor-lang,mrjbq7/factor,factor/factor,factor/factor,bpollack/factor,bjourne/factor,tgunr/factor,slavapestov/factor,bjourne/factor,AlexIljin/factor,mrjbq7/factor,bpollack/factor,tgunr/factor,sarvex/factor-lang,bjourne/factor,nicolas-p/factor,AlexIljin/factor,tgunr/factor,sarvex/factor-lang,sarvex/factor-lang,slavapestov/factor