Standing on structures such as crates, tables and bed will now look like it. (#79797)

## About The Pull Request
From the creator of 'cosmetic' elements such as footstep_override and
immerse...

I've made an element called elevation that nudges mobs a few pixels up
while standing on things like tables, crates and beds.

Screenshots of many clones of the same character standing on different
objects:
![the clone
army](https://github.com/tgstation/tgstation/assets/42542238/43ecdc25-f0d2-47fd-96dc-acafcf63483c)

## Why It's Good For The Game
It makes it look like the mob is actually standing on an elevated
surface.

## Changelog

🆑
add: Standing on structures such as crates, tables and bed will now look
like it.
/🆑

code/modules/mapfluff/ruins/lavalandruin_code/elephantgraveyard.dm

@@ -151,6 +151,8 @@
 	can_weld_shut = FALSE
 	cutting_tool = null
 	paint_jobs = null
+	elevation = 4 //It's a small mound.
+	elevation_open = 0
 
 	/// will this grave give you nightmares when opened
 	var/lead_tomb = FALSE