Missing extensions in differences from Haskell

[kl0tl]

The Extensions section of language/Differences-from-Haskell.md lists some extensions that seem mostly related to the type system, but not only: there’s also EmptyDataDecls and RebindableSyntax in there.

Do we want to keep the list focused on type system extensions? Otherwise I think the following extensions qualify for inclusion:

• ApplicativeDo
• BlockArguments
• DeriveFunctor
• DeriveGeneric
• GeneralisedNewtypeDeriving
• InstanceSigs
• LambdaCase
• LiberalTypeSynonyms
• MonoLocalBinds
• NamedFieldPuns
• NumericUnderscores
• StandaloneDeriving
• TypeOperators
• UndecidableInstances
• UnicodeSyntax

[natefaubion]

I think we should include any extension that applies.