feat: Add PriorityClass in glossary (#45608)

* feat: Add PriorityClass in glossary

* fix: Fix review comments

* fix: Fix review comments

* fix: Fix review comments

* Update content/en/docs/reference/glossary/priority-class.md

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

---------

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

content/en/docs/reference/glossary/priority-class.md

@@ -0,0 +1,20 @@
+---
+title: PriorityClass
+id: priority-class
+date: 2024-03-19
+full_link: /docs/concepts/scheduling-eviction/pod-priority-preemption/#priorityclass
+short_description: >
+  A mapping from a class name to the scheduling priority that a Pod should have.
+aka:
+tags:
+- core-object
+---
+A PriorityClass is a named class for the scheduling priority that should be assigned to a Pod
+in that class.
+
+<!--more-->
+
+A [PriorityClass](/docs/concepts/scheduling-eviction/pod-priority-preemption/#how-to-use-priority-and-preemption)
+is a non-namespaced object mapping a name to an integer priority, used for a Pod. The name is
+specified in the `metadata.name` field, and the priority value in the `value` field. Priorities range from
+-2147483648 to 1000000000 inclusive. Higher values indicate higher priority.