Add One-Click Deploy Buttons #158

You have some great docs on how to deploy to various services, but to make it even easier I'd love to see something like a Deploy to Heroku button (one click deploy w/ form-fill in for ENV vars) https://devcenter.heroku.com/articles/heroku-button

Not sure if other cloud providers have something similar, but if so that could be great too.

[Edit: Looks like Azure has another thing, just to give devs multiple options for easy one-click deploy: https://azure.microsoft.com/en-us/blog/deploy-to-azure-button-for-azure-websites-2/ ]