Add CONTRIBUTORS.md

[VladimirAlexiev]

I want to add a list of

• notable shapes tools implementors
• people who contributed to this project

Unlike a normal CONTRIBUTORS.md, I want to add 1-2 sentences per person and affiliation. The idea is to give some background, and help with community building.

Or will this sound like self-aggrandising?

[VladimirAlexiev]

@amivanoff @dontcallmedom @tpluscode @TallTed What do you think?

[TallTed]

No immediate objection. It could sound like self-aggrandising if only a few contributors are listed, with each listing written by that contributor. Making sure to list all contributors (above some lower-limit?), and including some detail about each, would help ameliorate that concern.