Add a lint check for incorrectly indented code blocks. (#1800)

Fixed a problem reported by the link check.

content_zh/docs/concepts/security/rbac/index.md

@@ -30,7 +30,7 @@ Istio 的 RBAC 引擎做了下面两件事：
 
 ### 请求上下文
 
-在当前版本中，Istio RBAC 引擎被实现为一个 [Mixer 适配器](/docs/concepts/policies-and-telemetry/#adapter)。请求上下文则作为[授权模板](https://github.com/istio/istio/blob/master/mixer/template/authorization/template.proto)的实例。请求上下文包含请求和授权模块需要环境的所有信息。特别是两个部分：
+在当前版本中，Istio RBAC 引擎被实现为一个 [Mixer 适配器](/docs/concepts/policies-and-telemetry/#adapters)。请求上下文则作为[授权模板](https://github.com/istio/istio/blob/master/mixer/template/authorization/template.proto)的实例。请求上下文包含请求和授权模块需要环境的所有信息。特别是两个部分：
 
 * 主题 包含调用者标识的属性列表，包括`"user"` name/ID，主题属于`“group”`，或者关于主题的任意附加属性，比如命名空间、服务名称。
 

content_zh/docs/tasks/traffic-management/fault-injection/index.md

@@ -100,40 +100,40 @@ Istio 的故障注入规则可帮助您识别此类异常，而不会影响最
 
 1. 为用户 “jason” 创建故障注入规则发送 HTTP 中止
 
-   {{< text bash >}}
+    {{< text bash >}}
-   $ istioctl replace -f @samples/bookinfo/networking/virtual-service-ratings-test-abort.yaml@
+    $ istioctl replace -f @samples/bookinfo/networking/virtual-service-ratings-test-abort.yaml@
-   {{< /text >}}
+    {{< /text >}}
 
-   确认已创建规则
+    确认已创建规则
 
-   {{< text bash yaml >}}
+    {{< text bash yaml >}}
-   $ istioctl get virtualservice ratings -o yaml
+    $ istioctl get virtualservice ratings -o yaml
-   apiVersion: networking.istio.io/v1alpha3
+    apiVersion: networking.istio.io/v1alpha3
-   kind: VirtualService
+    kind: VirtualService
-   metadata:
+    metadata:
-     name: ratings
+      name: ratings
-     ...
+      ...
-   spec:
+    spec:
-     hosts:
+      hosts:
-     - ratings
+      - ratings
-       http:
+        http:
-     - fault:
+      - fault:
-         abort:
+          abort:
-           httpStatus: 500
+            httpStatus: 500
-           percent: 100
+            percent: 100
-       match:
+        match:
-       - headers:
+        - headers:
-           cookie:
+            cookie:
-             regex: ^(.*?;)?(user=jason)(;.*)?$
+              regex: ^(.*?;)?(user=jason)(;.*)?$
-       route:
+        route:
-       - destination:
+        - destination:
-           host: ratings
+            host: ratings
-           subset: v1
+            subset: v1
-     - route:
+      - route:
-       - destination:
+        - destination:
-           host: ratings
+            host: ratings
-           subset: v1
+            subset: v1
-   {{< /text >}}
+    {{< /text >}}
 
 1.  观察应用程序行为
 

scripts/lint_site.sh

@@ -56,6 +56,13 @@ check_content() {
 check_content content --en-us
 check_content content_zh --zh-cn
 
+grep -nr -e "ERROR: markdown" ./public
+if [ "$?" == "0" ]
+then
+    echo "Ensure text blocks are either not indented, or indented by a multiple of 4 spaces"
+    FAILED=1
+fi
+
 htmlproofer ./public --check-html --assume-extension --timeframe 2d --storage-dir .htmlproofer --url-ignore "/localhost/,/github.com/istio/istio.github.io/edit/master/,/github.com/istio/istio/issues/new/choose/"
 if [ "$?" != "0" ]
 then