good stuff

README.md: Greatly updated. Will do more in future.
administration.lua: Administrators will now be promoted to group admins upon joining an administrated
group.
drua-tg: Squashed all luacheck warnings.
chatter.lua: Mostly rewritten; things actually make sense now.
xkcd.lua: Slight styling change.
patterns.lua: Squashed a warning.

plugins/patterns.lua

@@ -12,7 +12,8 @@ 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(
+	local res
+	res, output = pcall(
 		function()
 			return output:gsub(m1, m2)
 		end