fix(markdown-it-anchor): Add aria-label in anchors

Author: ktquez

config/chainMarkdown.js

@@ -0,0 +1,9 @@
+functionchainMarkdown(config){
+config
+.plugin('anchor')
+.tap(([options])=>[
+Object.assign(options,{permalinkAttrs: ()=>({'aria-label': 'Anchor'})})
+])
+}
+
+module.exports=chainMarkdown

index.js

@@ -1,6 +1,8 @@
 constplugins=require('./config/plugins')
+constchainMarkdown=require('./config/chainMarkdown')
 
 module.exports={
 extend: '@vuepress/theme-default',
- plugins
+ plugins,
+ chainMarkdown
 }