Let me state this, I love it when the devs put out a gameplay example of their wars with the AI.
But, AFAIK, it's not easy to gather, and properly order screenshots, plus memories fade.
One suggestion that was made when it was announced that the epic generator feature would be postponed, was to just have the game take a screenshot at a particular time and let the player fill in the blanks.
Well, I propose more.
The most similiar feature of another game that I know of is the picture books of the Sims games.
Add a "Take Screenshot" button to the game, but when you take a screenshot, an interface comes up that allows you to type a what you wish to type describing the situation. You can have the AI suggest certain times when it would be good to take a picture.
All this (again, similiar to the Sims games) would go into a scrapbook or a form of a simplified HTML editor where you can write up the whole epic as you please, placing images where necessary, and uploading the entire thing on the internet to post here
This may be a little rough, it may even have been proposed before, but I hope you can find some ideas here.
God bless
PegasusJF