Add example to wiki of writing simple bookmark functions for modes not having them

^{Originally posted by **amno1** February 16, 2024}
Is there some before/after hook I can hook a function into before the bookmark is opened?

I would like to restore a Sly session, with sbcl and a custom saved image. I am thinking of:

open bookmarked asdf file or at least project directory
start sly with a given compiler (I have different builds of sbcl) and saved core image

I haven't looked much at the code; I have just installed it and played a bit with it, so I am not very familiar with it. I see the activities--bookmark-buffer function.; or in activites--serialize/deserialize?

I could then add something to before (deserialize) hook to run Sly and wait until repl is up and running.

Or perhaps there is already a better place or a better way?