I think with vim-wiki you can set anchors (from the help):
A wikilink, interwiki link or diary link can be followed by a '#' and the name
of an anchor. When opening a link, the cursor jumps to the anchor. >
[[Todo List#Tomorrow|Tasks for tomorrow]]
To jump inside the current wiki file you can omit the file: >
There are probably better ways but you could the help functionality as long as the filetype being help is ok. I basically use it to write down things I'm learning as I keep learning how to use gvim, it's only been 20 years :).
At the moment I have one file that I edit elsewhere then copy to where the help file is as an archive. It's hit 1600 lines so I'll ...