feat: player.delete() function and update documentation

doc/en/scripting/builtins/libplayer.md

@@ -1,5 +1,17 @@
 # *player* library
 
+```lua
+player.create(name: str) -> int
+```
+
+Creates a player and returns id.
+
+```lua
+player.delete(id: int)
+```
+
+Deletes a player by id.
+
 ```lua
 player.get_pos(playerid: int) -> number, number, number
 ```