Adding absorption and xp API, and weather control (#540)

* fixes #537
* fixes  #547

docs/scarpet/api/Entities.md

@@ -396,6 +396,18 @@ Number indicating remaining entity health, or `null` if not applicable.
 
 Retrieves player hunger related information. For non-players, returns `null`.
 
+### `query(e, 'absorption')`
+
+Gets the absorption of the player (yellow hearts, e.g when having a golden apple.)
+
+### `query(e,'xp')`
+### `query(e,'xp_level')`
+### `query(e,'xp_progress')`
+### `query(e,'score')`
+
+Numbers related to player's xp. `xp` is the overall xp in the bar, `xp_level` is the levels seen in the hotbar,
+`xp_points` is a float between 0 and 1 indicating the percentage of the xp bar filled, and `score` is the score displayed upon death 
+
 ### `query(e, 'air')`
 
 Number indicating remaining entity health, or `null` if not applicable.
@@ -706,6 +718,17 @@ Will set entity on fire for `ticks` ticks. Set to 0 to extinguish.
 
 Modifies directly player raw hunger components. Has no effect on non-players
 
+### `modify(e, 'absorption', value)`
+
+Sets the absorption value for the player. Each point is half a yellow heart.
+
+### `modify(e, 'add_xp', value)`
+### `modify(e, 'xp_level', value)`
+### `modify(e, 'xp_score', value)` 
+
+Manipulates player xp values - that's the method you probably want to use 
+to manipulate how much 'xp' an action should give.
+
 ### `modify(e, 'air', ticks)`
 
 Modifies entity air