Improve boilerplates by adding front-matter marker. (#3693)

Also fixed formatting of multi-paragraph callouts. There
was some unsightly extra spacing at the top and bottom of the callout
in that case.

content/about/contribute/creating-and-editing-pages/index.md

@@ -6,6 +6,7 @@ aliases:
     - /docs/welcome/contribute/writing-a-new-topic.html
     - /docs/reference/contribute/writing-a-new-topic.html
     - /about/contribute/writing-a-new-topic.html
+    - /create
 keywords: [contribute]
 ---
 

content/boilerplates/before-you-begin-egress.md

@@ -1,3 +1,5 @@
+---
+---
 ## Before you begin
 
 *   Setup Istio by following the instructions in the [Installation guide](/docs/setup/).

content/boilerplates/example.md

@@ -1,3 +1,5 @@
+---
+---
 This is some boilerplate *markdown* _text_.
 
 {{< text plain >}}

content/boilerplates/helm-security-warning.md

@@ -1,4 +1,5 @@
- 
+---
+---
 {{< warning >}}
 The instructions for using Helm with Tiller do not use secure defaults.  See
 the [Helm Security Guidelines](https://helm.sh/docs/using_helm/#securing-your-helm-installation)

content/boilerplates/kubectl-multicluster-contexts.md

@@ -1,3 +1,5 @@
+---
+---
 * The `kubectl` command is used to access both the `cluster1` and `cluster2` clusters with the `--context` flag.
   Use the following command to list your contexts:
 

content/boilerplates/start-httpbin-service.md

@@ -1,3 +1,5 @@
+---
+---
 *   Start the [httpbin]({{< github_tree >}}/samples/httpbin) sample.
 
     If you have enabled [automatic sidecar injection](/docs/setup/kubernetes/additional-setup/sidecar-injection/#automatic-sidecar-injection), deploy the `httpbin` service:

content/boilerplates/trace-generation.md

@@ -1,3 +1,5 @@
+---
+---
 To see trace data, you must send requests to your service. The number of requests depends on Istio's sampling rate.
 You set this rate when you install Istio. The default sampling rate is 1%. You need to send at least 100 requests before the first trace is visible.
 To send a 100 requests to the `productpage` service, use the following command:

content_zh/boilerplates/before-you-begin-egress.md

@@ -1,3 +1,5 @@
+---
+---
 ## 开始之前
 
 *   按照[安装指南](/zh/docs/setup/)中的说明安装 Istio。

content_zh/boilerplates/example.md

@@ -1,3 +1,5 @@
+---
+---
 这是一些样板 *markdown* 文本。
 
 {{< text plain >}}

content_zh/boilerplates/kubectl-multicluster-contexts.md

@@ -1,3 +1,5 @@
+---
+---
 * `kubectl` 能通过 `--context` 参数切换上下文，以支持对不同集群 `cluster1` 和 `cluster2` 的访问。
   使用如下命令列出现存的上下文：
 

content_zh/boilerplates/start-httpbin-service.md

@@ -1,3 +1,5 @@
+---
+---
 *   启动 [httpbin]({{< github_tree >}}/samples/httpbin) 样例程序。
 
     如果您启用了 [sidecar 自动注入](/zh/docs/setup/kubernetes/additional-setup/sidecar-injection/#sidecar-的自动注入), 通过以下命令部署 `httpbin` 服务：

content_zh/boilerplates/trace-generation.md

@@ -1,3 +1,5 @@
+---
+---
 要查看追踪数据，您必须向您的服务发送请求。请求的数量取决于 Istio 的采样率。
 您在安装 Istio 时设置过这个采样速率参数，默认采样率为 1%。
 在第一个追踪可见之前，您需要发送至少 100 个请求。

src/sass/misc/_callout.scss

@@ -24,6 +24,14 @@
     .content {
         display: table-cell;
         min-height: 100%;
+
+        p:first-of-type {
+            margin-top: 0;
+        }
+
+        p:last-of-type {
+            margin-bottom: 0;
+        }
     }
 
     &.tip {