Requires the library mod Collective. 

   This mod is part of The Vanilla Experience.

Advancement Screenshot is a client-side mod which can automatically document the journey through a world without having to remember to take screenshots manually. Every time an advancement is achieved, a screenshot will be taken. The same code as the screenshot key (F2) is used, so the screenshots are located in the default folder. Works in multiplayer environments with the mod only on the client.

There is a 1 second delay in between getting the advancement and the actual screenshot. This allows some time for the message in the top right to appear.

Configurable: ( how do I configure? )
showScreenshotTakenMessage (default = false): If enabled, shows the normal screenshot taken (same as F2) message when a screenshot is taken after an advancement.
takeScreenshotTickDelay (default = 20, min 0, max 100): How many ticks the mod should wait until it takes a screenshot. By default 1 second. 20 ticks = 1 second

Some screenshots automatically taken after an advancement:


You may freely use this mod in any modpack, as long as the download remains hosted within the CurseForge ecosystem.

Serilum.com contains an overview and more information on all mods available.

Comments are disabled as I'm unable to keep track of all the separate pages on each mod.
For issues, ideas, suggestions or anything else there is the Github repo. Thanks!