解决pr描述无法过滤构建，增加ci-skip帮助文档

src/main/java/com/gitee/jenkins/gitee/hook/model/MergeRequestObjectAttributes.java

@@ -110,6 +110,10 @@ public class MergeRequestObjectAttributes {
         this.description = description;
     }
 
+    public void setBody(String description) {
+        this.description = description;
+    }
+
     public Project getSource() {
         return head.getProject();
     }

src/main/resources/com/gitee/jenkins/trigger/GiteePushTrigger/config.jelly

@@ -26,13 +26,10 @@
       </f:entry>
     </table>
   </f:entry>
-  <f:entry title="${%Enable.CI.Skip}" field="ciSkip">
+  <f:entry title="${%Enable.CI.Skip}" field="ciSkip" help="/plugin/gitee-jenkins-plugin/help/help-ci-skip.html">
     <f:checkbox default="true"/>
   </f:entry>
-  <f:entry title="${%Ignore.WIP.Merge.Requests}" field="skipWorkInProgressMergeRequest">
-    <f:checkbox default="true"/>
-  </f:entry>
-  <f:entry title="${%Set.Build.Desctiption}" field="setBuildDescription">
+  <f:entry title="${%Ignore.WIP.Merge.Requests}" field="skipWorkInProgressMergeRequest" help="/plugin/gitee-jenkins-plugin/help/help-wip-pull-request.html">
     <f:checkbox default="true"/>
   </f:entry>
   <f:entry title="${%Allowed.branches}">

src/main/webapp/help/help-ci-skip.html

@@ -0,0 +1,4 @@
+<div>
+  For Push hook: skip build if the commit message contains <code>[ci skip]</code>.
+  For Pull Request hook: skip build if the pull request body contains <code>[ci skip]</code>.
+</div>

src/main/webapp/help/help-ci-skip_zh_CN.html

@@ -0,0 +1,8 @@
+<div>
+  <p>
+  代码推送触发: 若推送的最后一个提交的描述信息包含 <code>[ci skip]</code>，则不触发构建。
+  </p>
+  <p>
+  PR 操作触发: 若 PR 的内容描述信息包含 <code>[ci skip]</code>，则不触发构建。
+  </p>
+</div>

src/main/webapp/help/help-wip-pull-request.html

@@ -0,0 +1,3 @@
+<div>
+  Ignore WIP Merge Requests
+</div>

src/main/webapp/help/help-wip-pull-request_zh_CN.html

@@ -0,0 +1,3 @@
+<div>
+  过滤正在进行构建的 Pull Request，防止同一个 PR 同时进行多次构建。
+</div>