Put home page in left nav. (#3157)

* Put home page in left nav.

* Experiment

* Update nav.

* Remove 2 topics from TOC check.

_data/docs-home.yml

@@ -3,6 +3,14 @@ abstract: "Documentation for using and learning about Kubernetes."
 toc:
 - docs/home/index.md
 
+- title: Kubernetes Documentation Home
+  path: index.md
+
+- title: Release Notes
+  path: https://github.com/kubernetes/kubernetes/releases/
+- title: Release Roadmap
+  path: https://github.com/kubernetes/kubernetes/milestones/
+
 - title: Contributing to the Kubernetes Docs
   section:
   - editdocs.md
@@ -12,12 +20,5 @@ toc:
   - docs/home/contribute/page-templates.md
   - docs/home/contribute/review-issues.md
   - docs/home/contribute/style-guide.md
-
-- title: Release Notes
-  path: https://github.com/kubernetes/kubernetes/releases/
-- title: Release Roadmap
-  path: https://github.com/kubernetes/kubernetes/milestones/
-- docs/home/deprecation-policy.md
-- docs/home/security.md