message: chore(website): add "clear" script
diff: "start": "docusaurus start --no-open --poll",
  "build": "docusaurus build",
  "swizzle": "docusaurus swizzle",
  - "deploy": "docusaurus deploy"
  + "deploy": "docusaurus deploy",
  + "clear": "docusaurus clear"
  },
  "dependencies": {
  "@docusaurus/core": "2.0.0-beta.14",
  