Correct typo (#2015)

* Correct typo

* short title for nav menu

Author: gliptak

docs/install/Knative-with-Ambassador.md

@@ -1,6 +1,6 @@
 ---
 title: "Installing Knative with Ambassador"
-linkTitle: "Ambassador API Gatway and Knative"
+linkTitle: "Ambassador API Gateway"
 weight: 15
 type: "docs"
 ---