Modify look (#848)

* Added modify(e,'look',...

* Added modify(e,'look',...

* Not change yaw and pitch if vector length is 0 or straight up/down

* Added to docs

* Update docs/scarpet/api/Entities.md

Co-authored-by: gnembon <41132274+gnembon@users.noreply.github.com>

docs/scarpet/api/Entities.md

@@ -589,6 +589,12 @@ Changes entity's location in the specified direction.
 
 Changes entity's pitch or yaw angle.
 
+### `modify(e, 'look', x, y, z), modify(e, 'look', [x,y,z] )`
+
+Sets entity's 3d vector where the entity is looking.
+For cases where the vector has a length of 0, yaw and pitch won't get changed.
+When pointing straight up or down, yaw will stay the same.
+
 ### `modify(e, 'head_yaw', angle)`, `modify(e, 'body_yaw', angle)`
 
 For living entities, controls their head and body yaw angle.