Updating Liveness and Readiness Docs (#3494)

* adding documentation for TCP checks, replacing "discussion" section with more detailed "configuration" section, other small tweaks

* some line breaks and a small tweak

* tweaking config section

* fixing problems with http get field descriptions, more detailed TCP example

docs/tasks/configure-pod-container/tcp-liveness-readiness.yaml

@@ -0,0 +1,22 @@
+apiVersion: v1
+kind: Pod
+metadata:
+  name: goproxy
+  labels:
+    app: goproxy
+spec:
+  containers:
+  - name: goproxy
+    image: gcr.io/google_containers/goproxy:0.1
+    ports:
+    - containerPort: 8080
+    readinessProbe:
+      tcpSocket:
+        port: 8080
+      initialDelaySeconds: 5
+      periodSeconds: 10
+    livenessProbe:
+      tcpSocket:
+        port: 8080
+      initialDelaySeconds: 15
+      periodSeconds: 20