Adds wiki links to antag greeting messages (#15939)

* Wiki Links Pass 1

* Wiki Links Pass 2

Ash Walkers,
Terror Spider spawns,
Terror Spider event,
Construct transfer,
Xenomorphs

* Less hardcoding

code/modules/mob/living/carbon/alien/special/alien_embryo.dm

@@ -99,6 +99,7 @@
 			new_xeno.mind.assigned_role = SPECIAL_ROLE_XENOMORPH
 			new_xeno.mind.special_role = SPECIAL_ROLE_XENOMORPH
 			new_xeno << sound('sound/voice/hiss5.ogg',0,0,0,100)//To get the player's attention
+			to_chat(new_xeno, "<span class='motd'>For more information, check the wiki page: ([config.wikiurl]/index.php/Xenomorph)</span>")
 
 			if(gib_on_success)
 				owner.gib()

code/modules/mob/living/simple_animal/hostile/terror_spiders/ghost.dm

@@ -42,5 +42,6 @@
 		to_chat(user, "<span class='notice'>Someone else already took this spider.</span>")
 		return
 	key = user.key
+	to_chat(src, "<span class='motd'>For more information, check the wiki page: ([config.wikiurl]/index.php/Terror_Spider)</span>")
 	for(var/mob/dead/observer/G in GLOB.player_list)
 		G.show_message("<i>A ghost has taken control of <b>[src]</b>. ([ghost_follow_link(src, ghost=G)]).</i>")