Add changelog for LKE v1.3.0

Author: asauber

src/content/changelog/lke-1-3-0.md

@@ -0,0 +1,25 @@
+---
+title: Linode Kubernetes Engine v1.3.0
+date: 2020-06-24T05:00:00.000Z
+version: 1.3.0
+changelog:
+  - Linode Kubernetes Engine
+---
+
+### Added
+
+* Added support for Kubernetes control plane versions 1.15.12, 1.16.11, 1.17.7.
+  All clusters were upgraded to these versions
+* Kubelet versions 1.15.10, 1.16.7, and 1.17.3 were made available for new and
+  recycled Nodes
+
+### Changed
+
+* Allow patch version skew between control plane and kubelet, so that we can
+  push kubelet upgrades asynchronously
+
+### Fixed
+
+* Deploy Linode Cloud Controller Manager v0.3.5 for all clusters to fix a bug
+  with NodeBalancer config rebuild for LoadBalancer Services
+