Fix the book gui placment to be in middle center instead of top center of the screen (bug report: MC-61489)
Description
This mod intent to fix MC-61489 by correctly positioning the gui of the book on the screen
Most of the fix come from [mworzala's gist](https://gist.github.com/mworzala/9a8d86803784c9c81aac77d9a7f9fb2b) so credit
to them for the fix, I just made it a mod. (They are not involved in the creation of it)