render links with markdown in emails

lib/markdown_to_html.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+module MarkdownToHtml
+  LINK_REGEXP = %r{\[([^\]]+)\]\((https?://[^)]+)\)}
+  LINK_REPLACE = '<a href="\2">\1</a>'
+
+  module_function
+
+  def call(text)
+    text.gsub(LINK_REGEXP, LINK_REPLACE)
+  end
+end