doc/nasmdoc.src: revamped context fall-through entry
doc/nasmdoc.src: revamped context fall-through entry

Distrotech/nasm,techkey/nasm,turingstudio/nasm,letolabs/nasm,techkey/nasm,techkey/nasm,turingstudio/nasm,letolabs/nasm,projedi/nasm,Distrotech/nasm,techkey/nasm,Distrotech/nasm,projedi/nasm,projedi/nasm,techkey/nasm,Distrotech/nasm,turingstudio/nasm,projedi/nasm,letolabs/nasm,turingstudio/nasm,projedi/nasm