Port Ampl to Elixir with "better tests fixtures"

We are using Elixir for our new project.
One of those projects involves having a CMS.
The content of the CMS needs to be rendered as AMP-Compliant HTML.
We have an _existing_ project that does this: https://github.com/dwyl/ampl
But it's node.js ... so we could _either_ add the node module to our workflow in a Pheonix Project
***or*** create an Elixir module which we can include in our Phoenix project.

Most of the README.md content can be "_recycled_".
Essentially the _mission_ of this project is to be "Ampl" for Elixir.

We _could_ use https://hex.pm/packages/earmark to convert Markdown to HTML.
@shouston3 please "_spike_" this tomorrow and see how far you get.
If you have questions about the `ampl` implementation, please ask @des-des 💬