[docs][glossary] Add page that lists all standardized k8s terms (#5657)

* Add comprehensive glossary page

Additional Authors:
* Andrew Chen <chenopis@users.noreply.github.com>
* Steve Perry <steveperry-53@users.noreply.github.com>

* incorporate Tim's feedback

* address zach's comments

* address more comments

* add additional crosslinking

* Add platform developer, tweak formatting for disambiguation cases or multiparagraph definitions.

_data/glossary/service.yaml

@@ -0,0 +1,9 @@
+id: service
+name: Service
+tags:
+- fundamental
+- core-object
+short-description: |
+  An API object that describes how to access applications, such as a set of [Pods](#term-pod), and can describe ports and load-balancers.
+long-description: |
+  The access point can be internal or external to the cluster.