Add importing html and save it to Article

Additionally defines a wizard logic which is partially unused yet.

lib/outlook/internal_tree.ex

@@ -0,0 +1,30 @@
+defmodule Outlook.InternalTree do
+
+  alias Outlook.InternalTree.{Html,Modifiers,Basic}
+  alias Outlook.HtmlPreparations.HtmlPreparation
+
+  def render_html(tree) do
+    tree
+    |> HtmlPreparation.strip_whitespace_textnodes()
+    |> Html.to_html()
+  end
+
+  def render_html_preview(tree) do
+    tree
+    |> partition_text
+    |> Html.to_html_preview("1")
+  end
+
+  require Logger
+  def apply_modifier(tree, modifier, uuids, opts \\ %{}) do
+    # Logger.info modifier
+    Modifiers.traverse_tree(tree, modifier, uuids, opts)
+  end
+
+  def partition_text(tree) do
+    # validate_sibling_collocation(tree)
+    tree
+    |> Basic.set_split_markers()
+    |> Basic.partition_textnodes()
+  end
+end