Best way to store multiple values of a key in a file, while also being able to append keys and values to said file?

I am currently programming a Soundboard. For that I would need to store the usergiven name of the sound, its path and a hotkey assigned to it. I also want the user to be able to add sounds whenever they like.

In a YAML document it would look something like this:

sounds:    sound1:        path: ...        name: ...        hotkey: ...    sound2:        path: ...        name: ...        hotkey: ...

Sadly I haven't found an easy way to append keys (sound3, sound4...) to a yaml like this.Is there an easy way to accomplish my goal?