Considering how pivotal the Endings are to the game and how many ways you can screw up getting a desired Ending, there should probably be an Endings page. It could go under The World>Endings, Your Character>Endings, etc. The tooltip, if possible, should also read something like "Spoilers ahead," although that's more or less implicit in a body of all knowledge about the game.
Endings Page
Summary:
There should probably be an Endings page.