xkcd.lua: Working again, but no more queries (for now).

fortune.lua: The bad spacing annoyed me to no end. Monospaced now.
patterns.lua: Error message upon malformed patterns.
readme.md: outdated, notice

plugins/patterns.lua

@@ -15,6 +15,16 @@ function patterns:action(msg)
 	local output = msg.reply_to_message.text or ''
 	local m1, m2 = msg.text:match('^/?s/(.-)/(.-)/?$')
 	if not m2 then return true end
+	local res, output = pcall(
+		function()
+			return output:gsub(m1, m2)
+		end
+	)
+	if res == false then
+		output = 'Malformed pattern!'
+		bindings.sendReply(self, msg, output)
+		return
+	end
 	output = output:gsub(m1, m2)
 	output = 'Did you mean:\n"' .. output:sub(1, 4000) .. '"'
 	bindings.sendReply(self, msg.reply_to_message, output)