update docs also in the tmpl file (grafana#186)

Signed-off-by: ShuzZzle <niclas.schad@gmail.com>

Author: nschad

README.md.gotmpl

@@ -88,18 +88,19 @@ alertmanager:
 ```
 And here are the related configuration values in AlertManager and Ruler:
 ```yaml
-alertmanager:
-  data_dir: /data/
-  storage:
-    type : local
-    local:
-      path: /data
-ruler:
-  rule_path: /data/rules
-  storage:
-    type : local
-    local:
-      directory: /tmp/rules
+config:
+  alertmanager:
+    data_dir: /data/
+    storage:
+      type : local
+      local:
+        path: /data
+  ruler:
+    rule_path: /data/rules
+    storage:
+      type : local
+      local:
+        directory: /tmp/rules
 ```
 In AlertManager, the data_dir and local storage directory should be the same.
 In the Ruler, there needs to be two separate volumes. One is read-only and serves as the location shared with the sidecar that contains all of the rules that were derived from configmaps (/tmp/rules). The other is read-write and used by the Ruler itself for its own management of rules, etc (/data).
@@ -130,6 +131,39 @@ data:
               title: Node {{"{{ $labels.instance }}"}} has high CPU usage
 
 ```
+Example ConfigMap containing an alertmanager-config:
+```yaml
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  annotations:
+    k8s-sidecar-target-directory: /data/fake
+  labels:
+    cortex_alertmanager: "1"
+  name: alertmanager-example-config
+data:
+  fake.yaml: |-
+    global:
+      resolve_timeout: 5m
+      http_config: {}
+      smtp_hello: localhost
+      smtp_require_tls: true
+    route:
+      receiver: team-X-mails
+      group_by:
+      - alertname
+      routes:
+      - receiver: "null"
+        match:
+          alertname: Watchdog
+      group_wait: 30s
+      group_interval: 5m
+      repeat_interval: 12h
+    receivers:
+    - name: 'team-X-mails'
+      email_configs:
+      - to: 'team-X+alerts@example.org'
+```
 
 {{ template "chart.requirementsSection" . }}