Fix README links to asset library (#1078)

This updates all links to point to the 4.2 demos instead of the 3.5 ones.

Co-authored-by: A Thousand Ships (she/her) <96648715+AThousandShips@users.noreply.github.com>

mobile/README.md

@@ -6,4 +6,4 @@ The Android IAP demo only runs on Android.
 
 Languages: All are GDScript
 
-Renderers: All are Compatibility
+Renderers: Mobile Sensors uses Mobile, the rest use Compatibility

mobile/android_iap/README.md

@@ -11,4 +11,4 @@ Renderer: Compatibility
 Note: There is a C# version available
 [here](https://github.com/godotengine/godot-demo-projects/tree/master/mono/android_iap).
 
-Check out this demo on the asset library: https://godotengine.org/asset-library/asset/532
+Check out this demo on the asset library: https://godotengine.org/asset-library/asset/2792

mobile/multitouch_cubes/README.md

@@ -6,7 +6,7 @@ Language: GDScript
 
 Renderer: Compatibility
 
-Check out this demo on the asset library: https://godotengine.org/asset-library/asset/141
+Check out this demo on the asset library: https://godotengine.org/asset-library/asset/2793
 
 ## Screenshots
 

mobile/multitouch_view/README.md

@@ -6,7 +6,7 @@ Language: GDScript
 
 Renderer: Compatibility
 
-Check out this demo on the asset library: https://godotengine.org/asset-library/asset/142
+Check out this demo on the asset library: https://godotengine.org/asset-library/asset/2794
 
 ## Screenshots
 

mobile/sensors/README.md

@@ -7,7 +7,7 @@ Language: GDScript
 
 Renderer: Mobile
 
-Check out this demo on the asset library: https://godotengine.org/asset-library/asset/143
+Check out this demo on the asset library: https://godotengine.org/asset-library/asset/2795
 
 ## Screenshots