textproc/gron.awk: New port

gron.awk transforms JSON into discrete assignments to make it easier to
grep for fields and to see absolute paths of those.

It is reasonably fast with Gawk/Mawk/GoAWK even on large-ish files. Slow
with BWK on big JSON files (100K+).

WWW: https://github.com/xonixx/gron.awk