Add glossory entry for ReplicaSet

_data/glossary/replica-set.yml

@@ -0,0 +1,13 @@
+id: replica-set
+name: ReplicaSet
+full-link: https://kubernetes.io/docs/concepts/workloads/controllers/replicaset/
+related:
+- replication-controller
+tags:
+- core-object
+- architecture
+short-description: >
+  ReplicaSet is the next-generation Replication Controller.
+long-description: >
+  ReplicaSet, like ReplicationController, ensures that a specified number of pods replicas are running at one time.
+  ReplicaSet supports the new set-based selector requirements as described in the labels user guide, whereas a Replication Controller only supports equality-based selector requirements.