index.md refers to six .html files with details on components, but when clicking on any of the links then some 404 message shows up instead of the expected .html file. I also don't see the .html files in the directory structure.

If the files exist, then please add them (or fix the links). If they don't exist yet, then please add some "under construction" placeholder.

Endless sky appears to use multi-threading and locking.

If developers inexperienced with the codebase (or inexperienced with threading) start making code-changes to structures shared between threads, then the risk of race-conditions and deadlocks could increase.

This request is to get some text in this documentation that describes which threads are used in the game and some text on which classes/areas/datastructures are expected to use locking (and when).