fix some broken links

upgrade all nginx examples to latest version
moved some examples from contrib to this repo

examples/customization/custom-errors/nginx/custom-default-backend.yaml

@@ -0,0 +1,31 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: nginx-errors
+  labels:
+    app: nginx-errors
+spec:
+  ports:
+  - port: 80
+    targetPort: 80
+    protocol: TCP
+    name: http
+  selector:
+    app: nginx-errors
+---
+apiVersion: v1
+kind: ReplicationController
+metadata:
+  name: nginx-errors
+spec:
+  replicas: 1
+  template:
+    metadata:
+      labels:
+        app: nginx-errors
+    spec:
+      containers:
+      - name: nginx-errors
+        image: aledbf/nginx-error-server:0.1
+        ports:
+        - containerPort: 80