Create pod eviction concept and glossary entries

  - Created glossary entries for manual and kubelet eviction
  - Created node-pressure-eviction.md and api-eviction.md
  - Merged content from eviction-policy.md and out-of-resource.md
  - Added note to kube-scheduler about node conditions
  - Deleted eviction-policy and out-of-resource.md
  - Redirected old topics
  - Change topic weights

content/en/docs/concepts/scheduling-eviction/_index.md

@@ -1,11 +1,37 @@
 ---
 title: "Scheduling, Preemption and Eviction"
 weight: 90
+content_type: concept
 description: >
   In Kubernetes, scheduling refers to making sure that Pods are matched to Nodes
   so that the kubelet can run them. Preemption is the process of terminating 
   Pods with lower Priority so that Pods with higher Priority can schedule on 
   Nodes. Eviction is the process of proactively terminating one or more Pods on
   resource-starved Nodes.
+no_list: true
 ---
 
+In Kubernetes, scheduling refers to making sure that {{<glossary_tooltip text="Pods" term_id="pod">}}
+are matched to {{<glossary_tooltip text="Nodes" term_id="node">}} so that the
+{{<glossary_tooltip text="kubelet" term_id="kubelet">}} can run them. Preemption
+is the process of terminating Pods with lower {{<glossary_tooltip text="Priority" term_id="pod-priority">}}
+so that Pods with higher Priority can schedule on Nodes. Eviction is the process
+of terminating one or more Pods on Nodes.
+
+## Scheduling
+
+* [Kubernetes Scheduler](/docs/concepts/scheduling-eviction/kube-scheduler/)
+* [Assigning Pods to Nodes](/docs/concepts/scheduling-eviction/assign-pod-node/)
+* [Pod Overhead](/docs/concepts/scheduling-eviction/pod-overhead/)
+* [Taints and Tolerations](/docs/concepts/scheduling-eviction/taint-and-toleration/)
+* [Scheduling Framework](/docs/concepts/scheduling-eviction/scheduling-framework)
+* [Scheduler Performance Tuning](/docs/concepts/scheduling-eviction/scheduler-perf-tuning/)
+* [Resource Bin Packing for Extended Resources](/docs/concepts/scheduling-eviction/resource-bin-packing/)
+
+## Pod Disruption
+
+{{<glossary_definition term_id="pod-disruption" length="all">}}
+
+* [Pod Preemption](/docs/concepts/scheduling-eviction/pod-priority-preemption/#preemption)
+* [Node-pressure Eviction](/docs/concepts/scheduling-eviction/node-pressure-eviction/)
+* [API-initiated Eviction](/docs/concepts/scheduling-eviction/api-eviction/)

content/en/docs/concepts/scheduling-eviction/api-eviction.md

@@ -0,0 +1,19 @@
+---
+title: API-initiated Eviction
+content_type: concept
+weight: 70
+---
+
+{{< glossary_definition term_id="api-eviction" length="short" >}} </br>
+
+You can request eviction by directly calling the Eviction API 
+using a client of the kube-apiserver, like the `kubectl drain` command. 
+This creates an `Eviction` object, which causes the API server to terminate the Pod. 
+
+API-initiated evictions respect your configured [`PodDisruptionBudgets`](/docs/tasks/run-application/configure-pdb/)
+and [`terminationGracePeriodSeconds`](/docs/concepts/workloads/pods/pod-lifecycle#pod-termination). 
+
+## {{% heading "whatsnext" %}}
+
+* Learn about [Node-pressure Eviction](/docs/concepts/scheduling-eviction/node-pressure-eviction/)
+* Learn about [Pod Priority and Preemption](/docs/concepts/scheduling-eviction/pod-priority-preemption/)

content/en/docs/concepts/scheduling-eviction/kube-scheduler.md

@@ -77,11 +77,9 @@ one of these at random.
 There are two supported ways to configure the filtering and scoring behavior
 of the scheduler:
 
-
 1. [Scheduling Policies](/docs/reference/scheduling/policies) allow you to configure _Predicates_ for filtering and _Priorities_ for scoring.
 1. [Scheduling Profiles](/docs/reference/scheduling/config/#profiles) allow you to configure Plugins that implement different scheduling stages, including: `QueueSort`, `Filter`, `Score`, `Bind`, `Reserve`, `Permit`, and others. You can also configure the kube-scheduler to run different profiles.
 
-
 ## {{% heading "whatsnext" %}}
 
 * Read about [scheduler performance tuning](/docs/concepts/scheduling-eviction/scheduler-perf-tuning/)