Kalkii Dynhvah's custom submariner coat (#22104)

Adds Kalkii Dynhvah's custom PRA submariner coat as per
[https://forums.aurorastation.org/topic/22881-kalkii-dynhvahs-submariner-coat/](https://forums.aurorastation.org/topic/22881-kalkii-dynhvahs-submariner-coat/).

Please do not merge until #22094 is merged, as this custom item is a
sub-type. It won't like, break anything but just to reduce issues.

Sprites were created by me, modified/based on Ebin-Halcyon's Honorable
Vanguard Battlecoat from Shiptest found in this PR:
https://github.com/shiptest-ss13/Shiptest/pull/2281

code/modules/customitems/item_defines.dm

@@ -1359,3 +1359,13 @@ All custom items with worn sprites must follow the contained sprite system: http
 	override_robotize_force_icon = 'icons/mob/human_races/fluff/vien_leg.dmi'
 	override_robotize_painted = FALSE
 	robotize_children = FALSE
+
+/obj/item/clothing/suit/storage/toggle/tajaran/pra_submarine/kalkii_coat //TD-17 submariner coat - Kalkii Dynhvah - CatsinHD
+	name = "TD-17 submariner coat"
+	desc = "A black leather coat with a Zshram fur collar found in use by the People's Republic of Adhomai's submarine service. \
+	This coat is missing the left sleeve past the shoulder, along with holes and rips throughout. Care has been taken to hem the \
+	edges of the holes, rips, and remains of the left sleeve. Rredouane's sword has been stenciled onto the back of the coat in white paint."
+	icon = 'icons/obj/custom_items/kalkii_coat.dmi'
+	icon_override = 'icons/obj/custom_items/kalkii_coat.dmi'
+	icon_state = "kalkii_coat"
+	item_state = "kalkii_coat"

html/changelogs/CatsinHD - KalkiiCustomItem.yml

@@ -0,0 +1,58 @@
+################################
+# Example Changelog File
+#
+# Note: This file, and files beginning with ".", and files that don't end in ".yml" will not be read. If you change this file, you will look really dumb.
+#
+# Your changelog will be merged with a master changelog. (New stuff added only, and only on the date entry for the day it was merged.)
+# When it is, any changes listed below will disappear.
+#
+# Valid Prefixes:
+#   bugfix
+#     - (fixes bugs)
+#   wip
+#     - (work in progress)
+#   qol
+#     - (quality of life)
+#   soundadd
+#     - (adds a sound)
+#   sounddel
+#     - (removes a sound)
+#   rscadd
+#     - (adds a feature)
+#   rscdel
+#     - (removes a feature)
+#   imageadd
+#     - (adds an image or sprite)
+#   imagedel
+#     - (removes an image or sprite)
+#   spellcheck
+#     - (fixes spelling or grammar)
+#   experiment
+#     - (experimental change)
+#   balance
+#     - (balance changes)
+#   code_imp
+#     - (misc internal code change)
+#   refactor
+#     - (refactors code)
+#   config
+#     - (makes a change to the config files)
+#   admin
+#     - (makes changes to administrator tools)
+#   server
+#     - (miscellaneous changes to server)
+#################################
+
+# Your name.
+author: CatsinHD
+
+# Optional: Remove this file after generating master changelog.  Useful for PR changelogs that won't get used again.
+delete-after: True
+
+# Any changes you've made.  See valid prefix list above.
+# INDENT WITH TWO SPACES.  NOT TABS.  SPACES.
+# SCREW THIS UP AND IT WON'T WORK.
+# Also, this gets changed to [] after reading.  Just remove the brackets when you add new shit.
+# Please surround your changes in  double quotes ("). It works without them, but if you use certain characters it screws up compiling. The quotes will not show up in the changelog.
+changes:
+  - rscadd: "Added Kalkii Dynhvah's custom item."