appendS is unintuitive in its argument ordering

[gergoerdi]

I can't tell if appendS is wrong or just unintuitive, but it seems the left-hand argument is routed to the right-hand side of the output and vice verse:

λ> appendS (toS [2 :: U4]) (toS [0 :: U8]) :: Seq U12
2 | ? .
λ> flip appendS (toS [2 :: U4]) (toS [0 :: U8]) :: Seq U12
512 | ? .

If this is indeed the intended behaviour, could you at least change the documentation from

given two signals of a1 and a2 width, respectively, pack them into a signal of a1 + a2 width.

to something like

given two signals of a1 and a2 width, respectively, pack them into a signal of a2 + a1 (sic!) width.