Add MainFramework and loading mask. Add animation to menu.

src/components/FitFullScreen.tsx

@@ -0,0 +1,11 @@
+import React from 'react'
+
+const FitFullScreen: React.FC<PropsWithChildren> = (props: PropsWithChildren) => {
+    return (
+        <>
+            <div id={'fit-fullscreen'}>{props.children}</div>
+        </>
+    )
+}
+
+export default FitFullScreen