Update ios-app tutorial to use ios_application for bundling instead of the deprecated bundling functionality of objc_binary.

This is to be coordinated with updating the example app (linked to within the tutorial)

--
MOS_MIGRATED_REVID=105430949
diff --git a/site/docs/tutorial/ios-app.md b/site/docs/tutorial/ios-app.md
index 8990817..fd99f6b 100644
--- a/site/docs/tutorial/ios-app.md
+++ b/site/docs/tutorial/ios-app.md
@@ -65,21 +65,38 @@
 
 ## Add an objc_binary rule
 
-The [`objc_binary`](/docs/build-encyclopedia.html#objc_binary) rule creates the
-bundled `.ipa` archive file for the application and also generates an Xcode
-project file.
+The [`objc_binary`](/docs/build-encyclopedia.html#objc_binary) rule creates a
+binary to be bundled in the application.
 
 Add the following to your `BUILD` file:
 
 ```python
 objc_binary(
-    name = "ios-app",
+    name = "ios-app-binary",
     srcs = [
         "UrlGet/main.m",
     ],
     deps = [
         ":UrlGetClasses",
     ],
+)
+
+```
+Note how the `deps` attribute references the output of the
+`UrlGetClasses` rule you added to the `BUILD` file above.
+
+## Add an ios_application rule
+
+The [`ios_application`](/docs/build-encyclopedia.html#ios_application) rule
+creates the bundled `.ipa` archive file for the application and also generates
+an Xcode project file.
+
+Add the following to your `BUILD` file:
+
+```python
+ios_application(
+    name = "ios-app",
+    binary = ":ios-app-binary",
     infoplist = "UrlGet/UrlGet-Info.plist",
 )
 ```
@@ -88,9 +105,6 @@
 [completed example](https://github.com/bazelbuild/examples/blob/master/tutorial/ios-app/BUILD)
 in the `master` branch of the GitHub repo.
 
-Again, note how the `deps` attribute references the output of the
-`UrlGetClasses` rule you added to the `BUILD` file above.
-
 ## Run the build
 
 Make sure that your current working directory is inside your Bazel workspace:
@@ -111,7 +125,6 @@
 ```bash
 INFO: Found 1 target...
 Target //ios-app:ios-app up-to-date:
-  bazel-bin/ios-app/ios-app_bin
   bazel-bin/ios-app/ios-app.ipa
   bazel-bin/ios-app/ios-app.xcodeproj/project.pbxproj
 INFO: Elapsed time: 3.765s, Critical Path: 3.44s