Introduce possibility to merge studies

As far as I'm aware it is not possible to merge the contents of two studies into multiple chapters of a single study. Why would you want to do that? You decide that multiple studies you have created are related thematically and want to organize them into multiple chapters of a single study. The only workaround I am aware of is that one can import the PGN from one study into another study. This ofcourse only imports the game moves but not the comments and annotation arrows. The later can be a lot of work to reproduce since one would have to enter all of it again. Therefore I'd like to propose Lichess introduces a possibility to copy or move a chapter of a study into another study. Thanks for considering it! EDIT: here an old archived post on the topic: https://lichess.org/forum/lichess-feedback/is-it-possible-to-merge-two-studies