add support to parse stdin in jsonlines format

[mojozinc]

stdin can be a stream of new line seperated jsons controlled by a -line cmd line flag

fix for #9

parse a -line flag from cmd line args, if set , treats the stdin as newline seperated jsons

can be tested manually go build . ./jsonui -line < test_big_line.jsonl

[gulyasm]

Thanks for the pull request @mojozinc ! I am doing a workshop till Wednesday, I will review it as soon as I'm back (around wednesday-thursday).

[Gerst20051]

This is a cool project would be cool to see it pick up some traction!

[gulyasm]

I'm sorry I don't reply to these PRs, I'm absolutely overwhelmed with my work and family. I will try to review these over the weekend.