Use `OverloadedLists` instead of `do` notation to concatenate `Html`

[Simon Meier]

I removed the Monad instance for the variant of Html which is serializable with embedded event-handler annotations. This currently means that one has to write things like

H.div $ mconcat
  [ H.p $ mconcat ["one", "two", "three"]
  , H.p "another paragraph"
  , H.p "perhaps a footer"
  ]

to concatenate Html. I think it would be worth a try to use OverloadedLists to simplify it to

H.div
  [ H.p ["one", "two", "three"]
  , H.p "another paragraph"
  , H.p "perhaps a footer"
  ]

one possible problem is that this would not play very well with Lucid's Term overloading trick. Moreover, we might be better off anyways by using lucids approach to a HTML EDSL in Haskell; i.e., just use a WriterT Html and overload the different application forms using the Term typeclass.

[Philip Kamenarsky]

I've been wondering about this. Why not just have something like:

div :: [Html a] -> Html a

...similar to purescript-react?