Update the release announcement
Update the release announcement

- add summary
- add entry for nonumsign opcode
- spell check

hammera/liblouis,liblouis/liblouis,BueVest/liblouis,liblouis/liblouis,BueVest/liblouis,liblouis/liblouis,hammera/liblouis,liblouis/liblouis,BueVest/liblouis,hammera/liblouis,BueVest/liblouis,hammera/liblouis,hammera/liblouis,liblouis/liblouis,BueVest/liblouis,BueVest/liblouis,liblouis/liblouis,hammera/liblouis