I see how to create links to another Agenda note with the right click menu.
I’d like to suggest another approach which is used in Quip (very different product!) that is very fast and keyboard based:
When you’re typing enter @ and as well as popping up a list of People, the list includes other Documents (Notes in Agenda-speak). As one keeps typing letters immediately after the @ symbol the list only shows Documents with those words. One can then select the Document using up arrow and return.
A cool feature is that one doesn’t have to type the exact name of the document - so typing @proposal finds documents that include the words “draft proposal”.
It’s very useful - and fast - to insert links like this just using the keyboard.
(Apologies if a similar functionality exists and I haven’t spotted it!)