Persist hand-made layout

Moving a node makes it stick in one place.

Maybe there's a way to store that information, `JSON.stringify`and put in the local storage.
From there there's only one step to printing the string to console and allowing user to put it in a file which would be loaded and interpreted every time the graph is drawn, so you can have some of the graph nodes maintain order between browsers and machines (assuming the file goes to the repository as documentation)

Start by locating the code that draws and moves graph nodes, then trace how node positions are represented. Investigate whether JSON.stringify and browser local storage can preserve positions, and determine how saved data would be loaded when the graph is drawn. Done means selected node layouts persist across sessions and can be printed for inclusion in repository documentation.

Written by the indexing model from the issue text.