Fixes #718 (#720)

Bad indexes are amazing.

code/__HELPERS/text.dm

@@ -338,7 +338,7 @@ proc/TextPreview(var/string,var/len=40)
 	var/regex/tag_markup
 	for (var/tag in (markup_tags - ignore_tags))
 		tag_markup = markup_regex[tag]
-		message = tag_markup.Replace(message, "[markup_tags[tag][1]]$2[markup_tags[tag][1]]")
+		message = tag_markup.Replace(message, "[markup_tags[tag][1]]$2[markup_tags[tag][2]]")
 
 	// ---Unload URL cache
 	for (var/ref in urls)

html/changelogs/skull132-PR-720.yml

@@ -0,0 +1,6 @@
+author: Skull132
+
+delete-after: True
+
+changes:
+  - bugfix: "Chat mark-up will work now. The closing tags in HTML are utilized properly once more."