extracted shared js libs from class 03 lib folder
add readme
Add the base homework files
Add lib directory from js-shared-libs as a subproject

git-subtree-dir: intro-exercises/lib
git-subtree-mainline: 275a171420d4b594bedf26af4069614af700d1e8
git-subtree-split: ad502a9066a30b7473e05bffc746a78f34d355f0