Are you using the search function?
Personally, I find it quite easy navigating with CONTROL + F, and searching for the concept I'm dealing with (e.g. river).
You can just keep tapping enter to cycle through matches, until you find the one (or ones) you are interested in.
I recently added a section to the document specifically to do with searching.
https://adventuron.io/documentation/#Searching
There is also the "Jump to section" functionality that is (somewhat hidden) behind the title of the text editor window.