Bump webpack-dev-server from 3.10.1 to 5.2.1

Bumps [webpack-dev-server](https://github.com/webpack/webpack-dev-server) from 3.10.1 to 5.2.1.
- [Release notes](https://github.com/webpack/webpack-dev-server/releases)
- [Changelog](https://github.com/webpack/webpack-dev-server/blob/master/CHANGELOG.md)
- [Commits](webpack/webpack-dev-server@v3.10.1...v5.2.1)

---
updated-dependencies:
- dependency-name: webpack-dev-server
  dependency-version: 5.2.1
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

package.json

@@ -36,7 +36,7 @@
     "style-loader": "^0.21.0",
     "webpack": "^4.6.0",
     "webpack-cli": "^3.1.1",
-    "webpack-dev-server": "^3.1.14"
+    "webpack-dev-server": "^5.2.1"
   },
   "author": "Majid Savalanpour <m.savalanpour@gmail.com>",
   "homepage": "https://github.com/savalanpour/react-component-countdown-timer",