chore(deps): update dependency markdown-it-anchor to v5 (#1620)

Author: renovate[bot]

package.json

@@ -125,7 +125,7 @@
         "less-plugin-npm-import": "^2.1.0",
         "lint-staged": "^7.2.2",
         "markdown-it": "^8.4.0",
-        "markdown-it-anchor": "^4.0.0",
+        "markdown-it-anchor": "^5.0.0",
         "marked": "^0.8.0",
         "merge2": "^1.2.1",
         "mini-css-extract-plugin": "^0.8.0",