Hexo6.x NexT v8.11.x 支持Mermaid图

NexT v8.11增加了对Mermaid的支持

https://theme-next.js.org/next-8-11-0-released/

使用方法

升级Hexo到V6.x, 升级NexT版本到V8.11.0，修改NexT配置文件，修改Hexo配置文件。
https://theme-next.js.org/docs/tag-plugins/mermaid.html

显示效果

https://github.com/mermaid-js/mermaid
https://github.com/mermaid-js/mermaid/blob/develop/README.zh-CN.md

流程图

代码：

```mermaid
graph TD
A[Hard] -->|Text| B(Round)
B --> C{Decision}
C -->|One| D[Result 1]
C -->|Two| E[Result 2]
```

显示效果：

graph TD
A[Hard] -->|Text| B(Round)
B --> C{Decision}
C -->|One| D[Result 1]
C -->|Two| E[Result 2]

顺序图

代码：

```mermaid
sequenceDiagram
Alice->>John: Hello John, how are you?
loop Healthcheck
    John->>John: Fight against hypochondria
end
Note right of John: Rational thoughts!
John-->>Alice: Great!
John->>Bob: How about you?
Bob-->>John: Jolly good!
```

显示效果

sequenceDiagram
Alice->>John: Hello John, how are you?
loop Healthcheck
    John->>John: Fight against hypochondria
end
Note right of John: Rational thoughts!
John-->>Alice: Great!
John->>Bob: How about you?
Bob-->>John: Jolly good!

甘特图

源码：

```mermaid
gantt
dateFormat  YYYY-MM-DD
section Section
Completed :done,    des1, 2014-01-06,2014-01-08
Active        :active,  des2, 2014-01-07, 3d
Parallel 1   :         des3, after des1, 1d
Parallel 2   :         des4, after des1, 1d
Parallel 3   :         des5, after des3, 1d
Parallel 4   :         des6, after des4, 1d
```

显示效果：

gantt
dateFormat  YYYY-MM-DD
section Section
Completed :done,    des1, 2014-01-06,2014-01-08
Active        :active,  des2, 2014-01-07, 3d
Parallel 1   :         des3, after des1, 1d
Parallel 2   :         des4, after des1, 1d
Parallel 3   :         des5, after des3, 1d
Parallel 4   :         des6, after des4, 1d

类图

源码：

```mermaid
classDiagram
Class01 <|-- AveryLongClass : Cool
<<interface>> Class01
Class09 --> C2 : Where am i?
Class09 --* C3
Class09 --|> Class07
Class07 : equals()
Class07 : Object[] elementData
Class01 : size()
Class01 : int chimp
Class01 : int gorilla
class Class10 {
  <<service>>
  int id
  size()
}
```

显示效果：

classDiagram
Class01 <|-- AveryLongClass : Cool
<<interface>> Class01
Class09 --> C2 : Where am i?
Class09 --* C3
Class09 --|> Class07
Class07 : equals()
Class07 : Object[] elementData
Class01 : size()
Class01 : int chimp
Class01 : int gorilla
class Class10 {
  <<service>>
  int id
  size()
}

状态图

源码：

```mermaid
stateDiagram
[*] --> Still
Still --> [*]
Still --> Moving
Moving --> Still
Moving --> Crash
Crash --> [*]
```

显示效果：

stateDiagram
[*] --> Still
Still --> [*]
Still --> Moving
Moving --> Still
Moving --> Crash
Crash --> [*]

饼图

源码：

```mermaid
pie
"Dogs" : 386
"Cats" : 85
"Rats" : 15
```

显示效果:

pie
"Dogs" : 386
"Cats" : 85
"Rats" : 15

用户体验旅程图journey

源码：

```mermaid
journey
title My working day
section Go to work
  Make tea: 5: Me
  Go upstairs: 3: Me
  Do work: 1: Me, Cat
section Go home
  Go downstairs: 5: Me
  Sit down: 3: Me
```

显示效果：

journey
title My working day
section Go to work
  Make tea: 5: Me
  Go upstairs: 3: Me
  Do work: 1: Me, Cat
section Go home
  Go downstairs: 5: Me
  Sit down: 3: Me