Add new typeclass, Reducible

This defines a typeclass `Reducible` which allows us to "reduce" pandoc
Inlines and Blocks, like so

    Emph [Strong [Str "foo", Space]] <++> Strong [Emph [Str "bar"]], Str
"baz"] =
        [Strong [Emph [Str "foo", Space, Str "bar"], Space, Str "baz"]]

So adjacent formattings and strings are appropriately grouped.

Another set of operators for `(Reducible a) => (Many a)` are also
included.

0 files changed, 0 insertions, 0 deletions