Update Main.hs file with Scotty example code.

app/Main.hs

@@ -1,4 +1,9 @@
-module Main where
+{-# LANGUAGE OverloadedStrings #-}
+
+import Web.Scotty
 
 main :: IO ()
-main = putStrLn "Hello, Haskell!"
+main = scotty 3000 $
+  get "/:word" $ do
+    beam <- pathParam "word"
+    html $ mconcat ["<h1>Scotty, ", beam, " me up!</h1>"]