refactor(markdown): compat with markdown-it-anchor 8.3.1+ (vuepress#482)

Co-authored-by: meteorlxy <meteor.lxy@foxmail.com>

Author: daniellandau

packages/@vuepress/markdown/package.json

@@ -30,7 +30,7 @@
     "@vuepress/shared": "2.0.0-beta.25",
     "@vuepress/utils": "2.0.0-beta.25",
     "markdown-it": "^12.2.0",
-    "markdown-it-anchor": "^8.3.0",
+    "markdown-it-anchor": "^8.4.1",
     "markdown-it-emoji": "^2.0.0",
     "mdurl": "^1.0.1"
   },

packages/@vuepress/markdown/src/plugins/anchorPlugin.ts

@@ -1,5 +1,4 @@
-import * as anchorPlugin from 'markdown-it-anchor'
-import type { AnchorOptions } from 'markdown-it-anchor'
+import anchorPlugin from 'markdown-it-anchor'
 
-export type AnchorPluginOptions = AnchorOptions
+export type AnchorPluginOptions = anchorPlugin.AnchorOptions
 export { anchorPlugin }

yarn.lock

@@ -7407,10 +7407,10 @@ map-obj@^4.0.0:
   resolved "https://registry.yarnpkg.com/map-obj/-/map-obj-4.2.1.tgz#e4ea399dbc979ae735c83c863dd31bdf364277b7"
   integrity sha512-+WA2/1sPmDj1dlvvJmB5G6JKfY9dpn7EVBUL06+y6PoljPkh+6V1QihwxNkbcGxCRjt2b0F9K0taiCuo7MbdFQ==
 
-markdown-it-anchor@^8.3.0:
-  version "8.3.0"
-  resolved "https://registry.yarnpkg.com/markdown-it-anchor/-/markdown-it-anchor-8.3.0.tgz#9e1a71766f778c382e5b6d3808d8c4d3a3b4ae30"
-  integrity sha512-YXMxKqZDH/MM/sFBZe+JQ/XFa7i8mIWZYkcY7jCGmpNNqcj2iS9Wyxy5devkUoL14NJOUt5IleD99D8StAwkXg==
+markdown-it-anchor@^8.3.1:
+  version "8.4.1"
+  resolved "https://registry.yarnpkg.com/markdown-it-anchor/-/markdown-it-anchor-8.4.1.tgz#29e560593f5edb80b25fdab8b23f93ef8a91b31e"
+  integrity sha512-sLODeRetZ/61KkKLJElaU3NuU2z7MhXf12Ml1WJMSdwpngeofneCRF+JBbat8HiSqhniOMuTemXMrsI7hA6XyA==
 
 markdown-it-container@^3.0.0:
   version "3.0.0"