delete unused download page and add a couple search tags

Change-Id: I8aad4703d575e2c336129e92a2b9ef448d21a4f9
diff --git a/docs/html/sdk/index.jd b/docs/html/sdk/index.jd
index 315c977..e1d7557 100644
--- a/docs/html/sdk/index.jd
+++ b/docs/html/sdk/index.jd
@@ -1,4 +1,5 @@
 page.title=Android SDK
+page.tags="download"
 page.template=sdk
 header.hide=1
 page.metaDescription=Download the official Android SDK to develop apps for Android-powered devices.