fix(cheesecakes): checkin broken resources

[michaellee8]

Currently index.html and product.html directly fetch css and js scripts from the github pages of startbootstrap, which has been drastically changed long ago, and resulted in broken links. This PR vendor all of those dependencies into this repo so it won't be broken. It also adds a quick note about how to install legacy dependencies in npm.

[michaellee8]

@lauriejim Please have a look at this.