create separate directory for js file

[ThanushaMandala]

example structure as below

weather-app/
├── index.html
├── css/
│ └── style.css
└── js/
└── app.js

[saakshi002]

Hi, can you assign me this task. @ThanushaMandala

[ThanushaMandala]

@saakshi002 assigned!!

[ShilpiBG12]

Hi, Can you please assign this task to me. Its very important for me for completing PRs for Hacktoberfest.