updated README with example 4 for CardView

Examples/CardView/CardView/Assets.xcassets/GraphKit.imageset/Contents.json

+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "filename" : "GraphKit.png",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}
\ No newline at end of file

Examples/CardView/CardView/Assets.xcassets/iTunesArtwork.imageset/Contents.json

+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "iTunesArtwork@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}
\ No newline at end of file

Examples/CardView/CardView/Assets.xcassets/ic_favorite_white.imageset/Contents.json

+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "filename" : "ic_favorite_white.png",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "ic_favorite_white@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "ic_favorite_white@3x.png",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}
\ No newline at end of file

Examples/CardView/CardView/Assets.xcassets/ic_search_white.imageset/Contents.json

+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "filename" : "ic_search_white.png",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "ic_search_white@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "ic_search_white@3x.png",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}
\ No newline at end of file