Bug - When closing effect is disabled the modal state does not transition to `Closed`

[anotherhale]

Bug - If Modal.setClosingEffect WithoutAnimate is configured the state remains in Closing status (does not transition to Closed)

[anotherhale]

To transition to the closing status the current code requires the state to transition to AnimationEnd - but this does not happen if ClosingEffect is set to WithoutAnimate.
I have come up with a solution that actually removes Effects all together and instead added another animation state FromNone and ToNone

type OpeningAnimation
    = FromTop
    | FromRight
    | FromBottom
    | FromLeft
    | FromNone

type ClosingAnimation
    = ToTop
    | ToRight
    | ToBottom
    | ToLeft
    | ToNone

These animations just have the transition animation set to 0s so that they essentially have the WithoutAnimate Effect.

If this is acceptable I will open a PR.

As you can see I also updated the Example code and will have a PR for that soon too.

Elm.modal.mp4

[anotherhale]

Configuring this is as simple as specifying FromNone or ToNone in the setOpeningAnimation or setClosingAnimation:

              div []
                [ button
                    [ class "button btn--width"
                    , onClick
                        (AlertClicked (Modal.openModal
                            ModalMsg
                            (configAlert
                                |> Modal.setOpeningAnimation FromNone
                                |> Modal.setClosingAnimation ToBottom
                            )
                        ) )
                    ]
                    [ i [ class "fi-x icon--margin" ] []
                    , i [ class "fi-arrow-down icon--margin" ] []
                    ]
                ]

[ondrej-tucek]

It's great, nice job Andy! I agree, open PR please.

As I'm now looking at to the README, there are missing any descriptions of OpeningAnimation, OpenedAnimation, ClosingAnimation and ClosingEffect types for users here. I mean, e.g. The OpeningAnimation type offers FromTop, FromRight, FromBottom, FromLeft and FromNone animations for modal window. All available animation types you can see (and of course use) below in the table...

I think it could be useful to have some kind of information for that. But it can be done at the end...