Fix the 404 error

CHANGELOG-1.9.md

@@ -626,7 +626,7 @@ Consider the following changes, limitations, and guidelines before you upgrade:
 
 ### **Multicluster**
 
-*   Development of Kubernetes Federation has moved to [github.com/kubernetes/federation](github.com/kubernetes/federation). This move out of tree also means that Federation will begin releasing separately from Kubernetes. Impact: 
+*   Development of Kubernetes Federation has moved to [github.com/kubernetes/federation](https://github.com/kubernetes/federation). This move out of tree also means that Federation will begin releasing separately from Kubernetes. Impact: 
     *   Federation-specific behavior will no longer be included in kubectl
     *   kubefed will no longer be released as part of Kubernetes
     *   The Federation servers will no longer be included in the hyperkube binary and image. ([#53816](https://github.com/kubernetes/kubernetes/pull/53816),[ @marun](https://github.com/marun))
@@ -667,7 +667,7 @@ Consider the following changes, limitations, and guidelines before you upgrade:
 
 ## Known Issues
 
-This section contains a list of known issues reported in Kubernetes 1.9 release. The content is populated from the [v1.9.x known issues and FAQ accumulator](https://github.com/kubernetes/kubernetes/issues/57159](https://github.com/kubernetes/kubernetes/issues/57159).
+This section contains a list of known issues reported in Kubernetes 1.9 release. The content is populated from the [v1.9.x known issues and FAQ accumulator] [#57159](https://github.com/kubernetes/kubernetes/issues/57159).
 
 *   If you are adding Windows Server Virtual Machines as nodes to your Kubernetes environment, there is a compatibility issue with certain virtualization products. Specifically the Windows version of the kubelet.exe calls `GetPhysicallyInstalledSystemMemory` to get the physical memory installed on Windows machines and reports it as part of node metrics to heapster. This API call fails for VMware and VirtualBox virtualization environments. This issue is not present in bare metal Windows deployments, in Hyper-V, or on some of the popular public cloud providers.
 
@@ -763,7 +763,7 @@ As announced with the release of version 1.8, the Kubernetes Workloads API is at
 #### **Custom Resources**
 
 *   Validation of resources defined by a Custom Resource Definition (CRD) is now in beta ([#54647](https://github.com/kubernetes/kubernetes/pull/54647),[ @colemickens](https://github.com/colemickens))
-*   An example CRD controller has been added, at [github.com/kubernetes/sample-controller](github.com/kubernetes/sample-controller). ([#52753](https://github.com/kubernetes/kubernetes/pull/52753),[ @munnerz](https://github.com/munnerz))
+*   An example CRD controller has been added, at [github.com/kubernetes/sample-controller](https://github.com/kubernetes/sample-controller). ([#52753](https://github.com/kubernetes/kubernetes/pull/52753),[ @munnerz](https://github.com/munnerz))
 *   Custom resources served by CustomResourceDefinition objects now support field selectors for `metadata.name` and `metadata.namespace`. Also fixed an issue with watching a single object; earlier versions could watch only a collection, and so a watch on an instance would fail.  ([#53345](https://github.com/kubernetes/kubernetes/pull/53345),[ @ncdc](https://github.com/ncdc))
 
 #### **Other**