Add Elm boilerplate to project

Create a top-level client directory to store my Elm boilerplate.

client/src/Main.elm

@@ -0,0 +1,31 @@
+module Main exposing (main)
+
+import Browser
+import Html exposing (..)
+import Landing
+import Login
+import State
+
+
+subscriptions : State.Model -> Sub State.Msg
+subscriptions model =
+    Sub.none
+
+
+view : State.Model -> Html State.Msg
+view model =
+    case model.view of
+        State.Landing ->
+            Landing.render model
+
+        State.Login ->
+            Login.render model
+
+
+main =
+    Browser.element
+        { init = \() -> ( State.init, Cmd.none )
+        , subscriptions = subscriptions
+        , update = State.update
+        , view = view
+        }