add MessageBox doc

doc/source/handycontrol/extend_controls/messageBox/index.md

@@ -1,5 +1,40 @@
 ---
-title: 建设中
+title: MessageBox 消息对话框
 ---
 
-建设中
+HC重写了一套消息对话框，使用方式和原生一致.
+
+```cs
+public sealed class MessageBox : Window
+```
+
+# 属性
+
+|属性|描述|默认值|备注|
+|-|-|-|-|
+|Message|消息内容|||
+|Image|消息类型示意图|||
+|ImageBrush|消息类型示意图颜色|||
+|ShowImage|是否显示消息类型示意图|false|||
+
+# 方法
+
+|名称|说明|
+|-|-|
+| Success(string, string) | 显示一则成功消息 |
+| Info(string, string) | 显示一则通知消息 |
+| Warning(string, string) | 显示一则警告消息 |
+| Error(string, string) | 显示一则错误消息 |
+| Fatal(string, string) | 显示一则严重消息 |
+| Ask(string, string) | 显示一则询问消息 |
+| Show(MessageBoxInfo) | 显示一则自定义消息 |
+| Show(string, string, MessageBoxButton, MessageBoxImage, MessageBoxResult) | 显示一则消息 |
+| Show(Window, string, string, MessageBoxButton, MessageBoxImage, MessageBoxResult) | 显示一则消息 |
+
+# 案例
+
+```cs
+MessageBox.Show(Properties.Langs.Lang.GrowlAsk, Properties.Langs.Lang.Title, MessageBoxButton.YesNo, MessageBoxImage.Question);
+```
+
+![MessageBox](https://raw.githubusercontent.com/HandyOrg/HandyOrgResource/master/HandyControl/Resources/MessageBox.png)

doc/themes/next/source/css/_custom/custom.styl

@@ -1,5 +1,9 @@
 // Custom styles.
 
+.container{
+  min-height: 100%;
+}
+
 .container:before{
   content: "";
   opacity: 0.1;
@@ -8,9 +12,10 @@
   bottom: 0;
   right: 0;
   position: absolute;
-  z-index: -1; 
+  z-index: -1;
   background: url(https://raw.githubusercontent.com/HandyOrg/HandyOrgResource/master/HandyControl/Resources/cloud.png);
 }
+
 .posts-expand .post-body img {
   margin: 3px;
   display: inline;

src/Shared/HandyControlDemo_Shared/UserControl/Controls/WindowDemoCtl.xaml.cs

@@ -4,7 +4,6 @@ using HandyControl.Data;
 using HandyControl.Tools;
 using MessageBox = HandyControl.Controls.MessageBox;
 
-
 namespace HandyControlDemo.UserControl
 {
     public partial class WindowDemoCtl