updating readme and added jest

Author: soumsps

.gitignore

@@ -0,0 +1,2 @@
+# Nodejs
+/node_modules

README.md

@@ -1,2 +1,41 @@
-# leetcode problem solving repo
+# Leetcode problem solution
+
 Practice problem solving on leetcode
+
+## Prerequisites
+
+```bash
+Node.js/npm
+jest
+```
+
+## Installation
+
+```bash
+git clone https://github.com/soumsps/leetcode.git
+npm install
+```
+
+## How to run the test for solutions?
+
+> #### Example 1: For running test on single Leetcode problem
+
+```bash
+Run tests for 2020/01_January/LC1_TwoSum
+
+cd into the 2020/01_January/ directory
+Then run:
+
+jest --watch LC1_TwoSum
+```
+
+> #### Example 2: For running test on complete month (eg. 01_January, 02_Feburary) of year 2020
+
+```bash
+Run tests for 2020/01_January
+
+cd into 2020
+Then run:
+jest --watch 01_January
+jest --watch 02_Feburary
+```