A take at a TUI-based structural editor, which should eventually read
a type definition of a structure and some values, and build a GUI to
edit it.
So far you can only pipe it some restricted json (lists, strings and
floats) and “navigate” through the structure with the arrow keys.
Change-Id: I7c8546459ff86c766fc03723f732c7d9f863ceaa
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2862
Tested-by: BuildkiteCI
Reviewed-by: Profpatsch <mail@profpatsch.de>