While writing your code in Poet there is an option to persist the different stages of development. You are able to make commits with your current state of progress. Pretty much like we all do by using Git. Then later every commit becomes part of your Story. You can reference files directly so no need to copy/paste when something gets changed. Here is an example.
We may also consider Poet a publishing platform for web related articles. Everything is written in markdown and integrated with the Poet app which makes the blogging quite nice and painless. I did write couple of articles myself and I could say that the experience is much better then what I did so far. I'm usually going to a place to try my code, mock an example. Then I write the material locally on my machine and at the end I publish it somewhere. Now all these three activities are combined into one place - Poet.
There are couple of ways to use Poet. It depends of what you want to do. Here is a list of options which I think will meet most of your needs.
You can get your Story in a markdown or HTML format. Let's say that your are editing /e/o7Nw8WK93sg. If you add "story" at the end you will get a page (/e/o7Nw8WK93sg/story) styled by Poet. If you however add "story.md" the result will be your Story in a markdown format - /e/o7Nw8WK93sg/story.md. There are also story.json and story.html respectively for JSON and unstyled HTML export.
My favorite setup is a three column layout where on the very left one I have the editor and a console. In the middle I have the Story panel where I'm writing the article in markdown and on the right one I see the preview. Try it yourself here.Ready to try Poet?
Check this 5 minutes video to get an idea how Poet works.