Add picture to LDF/TPF specs

[RubenVerborgh]

by Nathan Ridley on the mailing list:

If I may offer feedback on the specification, a picture speaks a thousand words. Some kind of diagram, or simple example architecture illustrating how LDF is supposed to work from a client-server perspective, would go a long way toward facilitating a better understanding of the LDF concept.

[akuckartz]

:+1:

[alien-mcl]

This is out of hydra scope - closing it.