Updated Lua Examples (markdown)

Lua-Examples.md

@@ -2,5 +2,21 @@ By default Inbucket will load `inbucket.lua`, but you may use the `INBUCKET_LUA_
 
 ## Event trigger: after message stored
 
-Example prints details for each message stored to STDOUT.
+```lua
+-- Prints metadata of stored messages to STDOUT.
+function inbucket.after.message_stored(msg)
+  print("\n## message_stored ##")
 
+  print(string.format("mailbox: %s", msg.mailbox))
+  print(string.format("id: %s", msg.id))
+  print(string.format("from: %q <%s>",
+    msg.from.name, msg.from.address))
+
+  for i, to in ipairs(msg.to) do
+    print(string.format("to[%s]: %q <%s>", i, to.name, to.address))
+  end
+
+  print(string.format("date: %s", os.date("%c", msg.date)))
+  print(string.format("subject: %s", msg.subject))
+end
+```