Add notes to nodes?

Good job so far! Is there any plan to add text notes to nodes? I find it a very basic and useful function in other mindmaps software. The text note is not visible int he map structure but it can popup at the bottom or side. So it doesn't clutter the map when a lot of text is added.

No files, tests, or entry points are identified in the issue. First review the node model and the mindmap display and editing flows, then clarify where notes should be stored and displayed before defining what completion means.

Written by the indexing model from the issue text.