readme: deb: add the number of jobs to make from `nproc`
readme: deb: add the number of jobs to make from `nproc`

nany-lang/nanyc,nany-lang/nany,milipili/nany,milipili/nany,nany-lang/nany,milipili/nany,nany-lang/nanyc,nany-lang/nany,nany-lang/nanyc