feat: rewrite public UI component rendering using tunnels (#6117)

* feat: rewrite public UI component rendering using tunnels

* factor out into components

* comments

* fix variable naming

* fix not hiding welcomeScreen

* factor out AppFooter and memoize components

* remove `UIOptions.welcomeScreen` and render only from host app

* factor out tunnels into own file

* update changelog. Keep `UIOptions.welcomeScreen` as deprecated

* update changelog

* lint

---------

Co-authored-by: Aakansha Doshi <aakansha1216@gmail.com>

src/packages/excalidraw/CHANGELOG.md

@@ -15,8 +15,13 @@ Please add the latest change on the top under the correct section.
 
 ### Features
 
+- Welcome screen no longer renders by default, and you need to render it yourself. `UIOptions.welcomeScreen` option is now deprecated. [#6117](https://github.com/excalidraw/excalidraw/pull/6117)
 - `MainMenu`, `MainMenu.Item`, and `MainMenu.ItemLink` components now all support `onSelect(event: Event): void` callback. If you call `event.preventDefault()`, it will prevent the menu from closing when an item is selected (clicked on). [#6152](https://github.com/excalidraw/excalidraw/pull/6152)
 
+### Fixes
+
+- declare css variable for font in excalidraw so its available in host [#6160](https://github.com/excalidraw/excalidraw/pull/6160)
+
 ## 0.14.1 (2023-01-16)
 
 ### Fixes

src/packages/excalidraw/index.tsx

@@ -53,7 +53,6 @@ const ExcalidrawBase = (props: ExcalidrawProps) => {
       ...DEFAULT_UI_OPTIONS.canvasActions,
       ...canvasActions,
     },
-    welcomeScreen: props.UIOptions?.welcomeScreen ?? true,
   };
 
   if (canvasActions?.export) {