Update site to reflect --cpu and --apple_platform_type flags.

PiperOrigin-RevId: 220286740
diff --git a/site/docs/gettingstarted.md b/site/docs/gettingstarted.md
index a99861a..9ce5446 100644
--- a/site/docs/gettingstarted.md
+++ b/site/docs/gettingstarted.md
@@ -36,8 +36,9 @@
 
 Flags used for all build modes:
 
-*   `--config=$(platform)_$(arch)` - sets up predefined Bazel options for the
+*   `--cpu=$(platform)_$(arch)` - sets up predefined Bazel options for the
     architecture exposed by Xcode.
+*   `--apple_platform_type=` - corresponds to the above option mostly.
 *   `--xcode_version` - passes the version of Xcode that invokes the compilation
     script.