Corrects 200+ instances of "it's" where it should've been "its" instead (#85169)

## About The Pull Request

it's - conjunction of "it" and "is"
its - possessive form of "it"

grammar is hard, and there were a lot of places where "it's" was used
where it shouldn't have been. i went and painstakingly searched the
entire repository for these instances, spending a few hours on it. i
completely ignored the changelog archive, and i may have missed some
outliers. most player-facing ones should be corrected, though
## Why It's Good For The Game
proper grammar is good

## Changelog
🆑
spellcheck: Numerous instances of "it's" have been properly replaced
with "its"
/🆑

code/modules/projectiles/guns/bolt_types_explained.md

@@ -1,7 +1,7 @@
 # Balistic gun icon states explained
 
 
-For a unknown period of time, `/obj/item/gun/ballistic` used the wrong icon state for it's `bolt_type` and so, if you tried to copy how it worked to make your own gun, you'd get a broken sprite.  This documentation is intended to explain in detail what some of the variables and functions do, and how to make your own gun subtypes that work properly.
+For a unknown period of time, `/obj/item/gun/ballistic` used the wrong icon state for its `bolt_type` and so, if you tried to copy how it worked to make your own gun, you'd get a broken sprite.  This documentation is intended to explain in detail what some of the variables and functions do, and how to make your own gun subtypes that work properly.
 
 ## Bolt Types
 The easiest thing to screw up.  For a long time, `/obj/item/gun/ballistic` had `bolt_type` set to `BOLT_TYPE_STANDARD` when the sprite was configured to use `BOLT_TYPE_LOCKING` sprites.  Nobody noticed, because it wasn't obtainable through normal gameplay, and the Mosin which was broken by it only has like 3 pixels missing.

code/modules/projectiles/projectile/energy/photon.dm

@@ -37,7 +37,7 @@
 		do_sparks(rand(1, 4), FALSE, src)
 
 /**
- * When traveling to a new turf, throws a probability to generate a hotspot across it's path.
+ * When traveling to a new turf, throws a probability to generate a hotspot across its path.
  */
 /obj/projectile/energy/photon/proc/scorch_earth(turf/open/floor/source, atom/movable/arrived, atom/old_loc, list/atom/old_locs)
 	SIGNAL_HANDLER