Update deployment section of website

[ryanto]

This is a placeholder issue for updating the deployment section of the website: https://ember-fastboot.com/docs/deploying

The idea is to break down the levels of abstraction for running FastBoot in production.

High level:

• FastBoot App Server
• Prember

Medium level (is that a thing?)

• Middleware

Low level

• App.visit

Also, we can have guides for how to setup a FastBoot app on Heroku and Netlify. TBD on which services to write guides for.

Related:

#85
#87