Make label form of url/link posting regex support mailto

lib/post/markdown/markdown.js

@@ -11,7 +11,7 @@ const greentextRegex = /^>((?!>\d+|>>/\w+(/\d*)?|>>#
 	, spoilerRegex = /\|\|([\s\S]+?)\|\|/gm
 	, detectedRegex = /\(\(\((.+?)\)\)\)/gm
 	/* eslint-disable no-useless-escape */
-	, linkRegex = /\[(?<label>[^\[][^\]]*?)\]\((?<url>(?:&#x2F;[^\s<>\[\]{}|\\^)]+|https?\:&#x2F;&#x2F;[^\s<>\[\]{}|\\^)]+))\)|(?<urlOnly>https?\:&#x2F;&#x2F;[^\s<>\[\]{}|\\^]+)/g
+	, linkRegex = /\[(?<label>[^\[][^\]]*?)\]\((?<url>(?:&#x2F;[^\s<>\[\]{}|\\^)]+|https?\:&#x2F;&#x2F;[^\s<>\[\]{}|\\^)]+|mailto:[\w.@]+))\)|(?<urlOnly>https?\:&#x2F;&#x2F;[^\s<>\[\]{}|\\^]+)/g
 	, codeRegex = /(?:(?<language>[a-z+]{1,14})\r?\n)?(?<code>[\s\S]+)/i
 	, includeSplitRegex = /(\[code\][\s\S]+?\[\/code\])/gm
 	, splitRegex = /\[code\]([\s\S]+?)\[\/code\]/gm