Add format check badge to README.md

This commit adds a new badge for the format check workflow to the README.md file. The badge links to the relevant GitHub workflow, providing quick access to the status of code formatting checks.

Author: nicholasadamou

README.md

@@ -1,4 +1,4 @@
-# LeetCode Study Plan Solutions [![Python Unit Tests](https://github.com/daily-coding-problem/neetcode-150/actions/workflows/python-unittests.yml/badge.svg)](https://github.com/daily-coding-problem/neetcode-150/actions/workflows/python-unittests.yml)
+# LeetCode Study Plan Solutions [![Python Unit Tests](https://github.com/daily-coding-problem/neetcode-150/actions/workflows/python-unittests.yml/badge.svg)](https://github.com/daily-coding-problem/neetcode-150/actions/workflows/python-unittests.yml) [![Format Check](https://github.com/daily-coding-problem/leetcode-study-plans/actions/workflows/format-check.yml/badge.svg)](https://github.com/daily-coding-problem/leetcode-study-plans/actions/workflows/format-check.yml)
 
 ![Python](https://img.shields.io/badge/-Python-3776AB?style=flat-square&logo=python&logoColor=white)
 ![Pytest](https://img.shields.io/badge/-Pytest-0A9EDC?style=flat-square&logo=pytest&logoColor=white)