Create main.rede

[DataDink]

Let's do a sample app. No need for it to compile or work, just the intended code for the prompt.

[lstertz]

I've started some program examples in the Initial Examples branch, specifically in the specification/annexes/annex-d/ folder. Those examples are so far smaller than what I think you have in mind with this, but let's re-target this pull request to that branch with the file being a .md named to succinctly describe the example app that would be described there. We will probably build upon that with child pages that go through the different parts of the app and describe the code therein.

Our goal, as you've stated, isn't outright compilable code, so mixing in explanations of the code and splitting it across .md files should be fine and will allow it to be more presentable through the GitBook.