Consolidate YAML files [part-2] (#9236)

Changes that will help upcoming consolidation work:

- Add variable `githubWebsiteRaw` to config.toml to facilitate building
  links to raw YAML files
- Revise `codenew` shortcode to generate links to raw YAML files instead
  of github.com file view;
- Rename `artifacts` directory to `examples` to better reflect its usage;

Accompanied changes as show cases:

- Moved `deployment.yaml`, `deployment-update.yaml` and
  `deployment-scale.yaml` to the new `examples/application` subdirectory;
- Removed duplicate instances of the above YAML files in other
  directories;
- Update example_test.go to test the relocated YAML files and removed
  testing for files that no longer needed.

content/en/examples/application/deployment-update.yaml

@@ -0,0 +1,19 @@
+apiVersion: apps/v1 # for versions before 1.9.0 use apps/v1beta2
+kind: Deployment
+metadata:
+  name: nginx-deployment
+spec:
+  selector:
+    matchLabels:
+      app: nginx
+  replicas: 2
+  template:
+    metadata:
+      labels:
+        app: nginx
+    spec:
+      containers:
+      - name: nginx
+        image: nginx:1.8 # Update the version of nginx from 1.7.9 to 1.8
+        ports:
+        - containerPort: 80