Added Description

Author: mrinal1704

README.md

@@ -3,3 +3,8 @@
 ## Motivation
 This repo contains all my SQL solutions from Leetcode website in order to practice my SQL programming skills. It is still in progress
 and I will be posting it here as I am done attempting them everyday.
+
+## Description
+The Solutions are divided into three level of categories namely Easy, Medium, and Hard. Every category first contains the question and then followed by its respective solution.
+Link to the website is: https://leetcode.com/problemset/database/
+