message: fix(nested-scroll): docs
diff: "repository": {
  "type": "git",
  "url": "git@github.com:ustbhuangyi/better-scroll.git",
  - "directory": "packages/better-scroll"
  + "directory": "packages/nested-scroll"
  },
  "dependencies": {
  "@better-scroll/core": "^2.0.0-alpha.18"
  