Add demo/seed projects to README
Add demo/seed projects to README

yagitoshiro/power-assert,power-assert-js/power-assert,saneyuki/power-assert,saneyuki/power-assert,falsandtru/power-assert,yagitoshiro/power-assert,power-assert-js/power-assert,twada/power-assert,twada/power-assert,falsandtru/power-assert