Update internal documentation on host and target platform defaults.

PiperOrigin-RevId: 302443411
diff --git a/site/docs/platforms.md b/site/docs/platforms.md
index a265968..f993e9f 100644
--- a/site/docs/platforms.md
+++ b/site/docs/platforms.md
@@ -113,5 +113,5 @@
 command-line flags:
 
 *  `--host_platform` - defaults to `@bazel_tools//platforms:host_platform`
-
 *  `--platforms` - defaults to `@bazel_tools//platforms:target_platform`
+