Clear demo app's readme because it's not up to date

Author: ole

DemoApp/README.md

@@ -1,36 +1 @@
 #  SwiftUI Layout Inspector Demo App
-
-## Instructions
-
-1.  Edit the `subject: some View` property in `ContentView`. It should contain
-    the view tree you want to inspect.
-    
-2.  Add `.debugLayout()` at each point in the view tree where you want to
-    inspect the layout algorithm (what sizes are being proposed and returned). 
-        
-    Example of a `subject` property with a few inspection points:
-   
-    ```swift
-    var subject: some View {
-        Text("Hello world")
-            .debugLayout("Text")
-            .padding(10)
-            .debugLayout("padding")
-            .background {
-                Color.yellow
-                    .debugLayout("yellow")
-            }
-            .debugLayout("background")
-    }
-    ```
-
-4.  Build and run the app.
-
-    - The subject view is displayed on top.
-    - The table on the bottom displays the sizes that are being proposed at each
-      inspection point in the subject view ("Proposal", and the resulting view 
-      sizes ("Response").
-    - You can tap/click items in the grid to highlight the respective view.
-    - You can use the sliders to modify the size proposed to the subject view.
-    - Some views cache certain layout information. Press "Reset layout cache"
-      after modifying the sliders to reset the caches.