* testing the hook reveals it is called before `customize-image.sh` (proper english this time)
Mixed before and after in documentation of the hook. (if it can be used the same way as `customize-image.sh` will be tested tomorrow, i think if the image is not mounted, you cant do system settings)
* As it is triggered before mounting the overlay, it cannot be used exactly like the `customize-image.sh`
As it is triggered before mounting the overlay, it cannot be used exactly like the `customize-image.sh`
* mkdocs.yml cleanups and syntax highlight; add .editorconfig for *.md
* add work-in-progress docs for Extensions
* split hand-written and autogen docs for Extensions