styling improvements, including implementing alerts with phx hook to clear flash after bootstrap alert close event

lib/bones73k_web/views/layout_view.ex

@@ -7,4 +7,15 @@ defmodule Bones73kWeb.LayoutView do
       true -> Keyword.update(opts, :class, "active", fn c -> "#{c} active" end)
     end
   end
+
+  def alert_kinds do
+    [
+      success: "alert alert-success",
+      info: "alert alert-info",
+      error: "alert alert-danger",
+      warning: "alert alert-warning",
+      primary: "alert alert-primary",
+      secondary: "alert alert-secondary"
+    ]
+  end
 end