Add tooltip for addons in Hello Minikube page (#18156)

* Add tooltip for addons in Hello Minikube page

* Update glossary title and add more descriptive info

Co-Authored-By: Tim Bannister <tim@scalefactory.com>

Co-authored-by: Tim Bannister <tim@scalefactory.com>

content/en/docs/reference/glossary/addons.md

@@ -0,0 +1,16 @@
+---
+title: Add-ons
+id: addons
+date: 2019-12-15
+full_link: /docs/concepts/cluster-administration/addons/
+short_description: >
+  Resources that extend the functionality of Kubernetes.
+
+aka:
+tags:
+- tool
+---
+  Resources that extend the functionality of Kubernetes.
+
+<!--more-->
+[Installing addons](/docs/concepts/cluster-administration/addons/) explains more about using add-ons with your cluster, and lists some popular add-ons.

content/en/docs/tutorials/hello-minikube.md

@@ -170,7 +170,7 @@ Kubernetes [*Service*](/docs/concepts/services-networking/service/).
 
 ## Enable addons
 
-Minikube has a set of built-in addons that can be enabled, disabled and opened in the local Kubernetes environment.
+Minikube has a set of built-in {{< glossary_tooltip text="addons" term_id="addons" >}} that can be enabled, disabled and opened in the local Kubernetes environment.
 
 1. List the currently supported addons: