Populate Citrine City

This commit adds NPCs and signs to Citrine, doing some significant worldbuilding in the process. I considered adding an event where Oak greets you like how the Magma/Aqua Admins do on the ORAS Battle Resort, but it seemed a little too on-the-nose, y'know?

There was an issue where you wouldn't be walked out of doors automatically, which was quite immersion-breaking. That was because the door tile IDs weren't defined - this is fixed too.

Some map elements have been altered to facilitate the new changes, and obviously, some map sprite slots have been filled.

Importing and changing the Battle Tent is most likely my next task.

data/maps/objects/CitrineCity.asm

@@ -11,7 +11,19 @@ CitrineCity_Object:
 	warp_event 39, 30, VERMILION_CITY, 6
 
 	def_bg_events
+	bg_event 16, 27,  5 ; Citrine Shop
+	bg_event 16, 17,  6 ; Pokecenter
+	bg_event 20, 22,  7 ; Billboard 1
+	bg_event  5, 18,  8 ; Billboard 2
+	bg_event  9,  7,  9 ; Battle Tower
+	bg_event 25, 23, 10 ; City Sign
+	bg_event 21, 26, 11 ; Directions
+	bg_event 23,  7, 12 ; Garnet Cavern Sign
 
 	def_object_events
+	object_event 12, 18, SPRITE_BEAUTY, WALK, LEFT_RIGHT, 1 ; person
+	object_event  6,  9, SPRITE_HIKER,  WALK, LEFT_RIGHT, 2 ; person
+	object_event 20, 26, SPRITE_GENTLEMAN, STAY, UP, 3 ; person
+	object_event 10, 30, SPRITE_ROCKER, WALK, ANY_DIR, 4 ; person
 
 	def_warps_to CITRINE_CITY

data/maps/objects/CitrinePokecenter.asm

@@ -2,8 +2,8 @@ CitrinePokecenter_Object:
 	db $0 ; border block
 
 	def_warp_events
-	warp_event  3,  7, LAST_MAP, 6
-	warp_event  4,  7, LAST_MAP, 6
+	warp_event  3,  7, LAST_MAP, 3
+	warp_event  4,  7, LAST_MAP, 3
 
 	def_bg_events