Medical guide update

ACE 3 update [3.16.0](https://github.com/acemod/ACE3/releases/tag/v3.16.0) changed the logic of stitching action (stitching must be completed for each body part, instead of entire body) in medical system and it would be nice to mention it in medical guide.

> Medical Treatment - Change stitching action to be per-body-part (https://github.com/acemod/ACE3/pull/9005)