feature: process stdin and/or to stdout

[roycewilliams]

For some workflows, it would be very helpful if gramify could operate on stdin and/or send output to stdout.

[0xVavaldi]

STDIN is generally possible because gramify processes line-by-line. STDOUT has some issues however because gramify outputs a lot of duplicates. What approach would you recommend here for your considered usecases? Let the user figure it out, or not implement it to force the proper handling of the duplicates?

[roycewilliams]

Hot take: let the user decide what to do with duplicates.

[0xVavaldi]

Added a partial implementation of --stdout, but I quickly noticed that the way I handle file input & output needs a pretty big overhaul to neatly handle the implementation of stdin and out for more complex setups. So I would need to find some time and motivation to rework that