Pretty cool!
I like the concept and think I too don't document my work as often as I should, so a tool like this is super useful.
Quick Notes:
On boarding - after signing up - I am just shown collections, maybe a page to describe 3 things you can do - you already have it on the homepage, but to provide (Click on My Colletion (top nav) then Notes... etc.).
It's a little hard to find/see "My collections" as it's not part of the top nav. Collections show public collections so may want to adjust how.
Just some quick thoughts.
I also think a tool for capturing/storing design/ui elemnts (e.g. https://icebergs.com/site) might be another approach (sample tool, but also useful).
This is also assuming all my "projects" are public facing. It would be nice to be able to run/tunnel/some hack to capture local progress and showcase that.