I keep it in Yaml because that makes it easy to build upon it.
For example it lets you easily make your own project based on mine which renders the Yaml file in a way that is suitable for reading. Even if I add more attributes to each entry, your version will always stay user friendly by rendering only the attributes that you deem right for your interface.
If the info is intended to be read by humans, keep it in a human-readable format. That way your project is more likely to _have_ a future.
2. Embrace your tooling.
You are keeping it on Github. GH will render Markdown to HTML for you. Use that. Don't keep it in some format it won't render.
3. Choose the right tools.
YAML is for config files. This isn't a config file.
4. Think about what tools you chose and why.
It may be easy to parse YAML with code, but is that significantly different from how easy it is to parse Markdown with code?
Anyway. You do you. I am not telling you what to do or how to do it. I am merely trying to point out flaws with the current approach.