516 compatibility for browsers (#20652)

this is a bit of

https://github.com/cmss13-devs/cmss13/pull/8646
https://github.com/cmss13-devs/cmss13/pull/8875
https://github.com/cmss13-devs/cmss13/pull/8606
https://github.com/cmss13-devs/cmss13/pull/8607
https://github.com/cmss13-devs/cmss13/pull/8359
https://github.com/cmss13-devs/cmss13/pull/7860
( and thus https://github.com/ParadiseSS13/Paradise/pull/25105
https://github.com/ParadiseSS13/Paradise/pull/25205
https://github.com/ParadiseSS13/Paradise/pull/25363
https://github.com/ParadiseSS13/Paradise/pull/26423 and
https://github.com/ParadiseSS13/Paradise/pull/26433 )
https://github.com/tgstation/tgstation/pull/89766

in order to work properly - using the efficient storage method, instead
of the byond json method - github pages needs to be enabled and built
from the gh-pages branch. because yeah

---------

Co-authored-by: harryob <55142896+harryob@users.noreply.github.com>

code/modules/projectiles/guns/projectile/dartgun.dm

@@ -159,7 +159,7 @@
 			dat += SPAN_WARNING("The dart cartridge is empty!")
 		dat += " \[<A href='byond://?src=[REF(src)];eject_cart=1'>Eject</A>\]"
 
-	user << browse(dat, "window=dartgun")
+	user << browse(HTML_SKELETON(dat), "window=dartgun")
 	onclose(user, "dartgun", src)
 
 /obj/item/gun/projectile/dartgun/proc/check_beaker_mixing(var/obj/item/B)