glossary entry for PodPreset (kubernetes#7468)

* glossary entry for PodPreset

* Update podpreset.yaml

Author: MHBauer

_data/glossary/podpreset.yaml

@@ -0,0 +1,12 @@
+id: podpreset
+name: PodPreset
+tags:
+- operation
+short-description: >
+  An API object that injects information such as secrets, volume mounts,
+  and environment variables into pods at creation time.
+long-description: >
+  This object chooses the pods to inject information into using
+  standard selectors. This allows the podspec definitions to be
+  nonspecific, decoupling the podspec from environment specific
+  configuration.