chore: downgrade webpack

Downgrade to v4 since there's some incompatibility with vuepress.

Author: krisk

docs/.vuepress/config.js

@@ -114,8 +114,7 @@ function getPlugins() {
  'https://www.linkedin.com/sharing/share-offsite/?mini=true&url=@url&title=@title&summary=@description',
  type: 'popup',
  color: '#1786b1',
- icon:
- '<svg viewBox="0 0 1024 1024" xmlns="http://www.w3.org/2000/svg"><path d="M910.336 0H113.664A114.005333 114.005333 0 0 0 0 113.664v796.672A114.005333 114.005333 0 0 0 113.664 1024h796.672A114.005333 114.005333 0 0 0 1024 910.336V113.664A114.005333 114.005333 0 0 0 910.336 0zM352.256 796.330667H207.189333V375.466667h145.066667z m-72.021333-477.866667a77.824 77.824 0 0 1-81.237334-74.069333A77.824 77.824 0 0 1 280.234667 170.666667a77.824 77.824 0 0 1 81.237333 73.728 77.824 77.824 0 0 1-81.237333 73.386666z m582.314666 477.866667H716.8v-227.669334c0-46.762667-18.432-93.525333-73.045333-93.525333a84.992 84.992 0 0 0-81.237334 94.549333v226.304h-140.629333V375.466667h141.653333v60.757333a155.989333 155.989333 0 0 1 136.533334-71.338667c60.416 0 163.498667 30.378667 163.498666 194.901334z" /></svg>'
+ icon: '<svg viewBox="0 0 1024 1024" xmlns="http://www.w3.org/2000/svg"><path d="M910.336 0H113.664A114.005333 114.005333 0 0 0 0 113.664v796.672A114.005333 114.005333 0 0 0 113.664 1024h796.672A114.005333 114.005333 0 0 0 1024 910.336V113.664A114.005333 114.005333 0 0 0 910.336 0zM352.256 796.330667H207.189333V375.466667h145.066667z m-72.021333-477.866667a77.824 77.824 0 0 1-81.237334-74.069333A77.824 77.824 0 0 1 280.234667 170.666667a77.824 77.824 0 0 1 81.237333 73.728 77.824 77.824 0 0 1-81.237333 73.386666z m582.314666 477.866667H716.8v-227.669334c0-46.762667-18.432-93.525333-73.045333-93.525333a84.992 84.992 0 0 0-81.237334 94.549333v226.304h-140.629333V375.466667h141.653333v60.757333a155.989333 155.989333 0 0 1 136.533334-71.338667c60.416 0 163.498667 30.378667 163.498666 194.901334z" /></svg>'
  }
  },
  twitterUser: 'kirorisk',

package.json

@@ -95,7 +95,7 @@
  "vuepress-plugin-google-adsense": "^0.2.1",
  "vuepress-plugin-smooth-scroll": "^0.0.10",
  "vuepress-plugin-social-share": "^1.1.0",
- "webpack": "^5.64.0",
+ "webpack": "4.46.0",
  "webpack-cli": "^4.9.1"
   },
  "engines": {