Add Eslint and Prettier Configuration

[KshitijDarekar]

Is your feature request related to a problem? Please describe.
Tools like ESLint and Prettier make it easier for developers to enforce their team's chosen coding standards.

Describe the solution you'd like

• Setup Eslint
• Setup Prettier
• Airbnb Style
• For both Frontend and Backend

Describe alternatives you've considered
In future, we can also try adding husky, but for now, we can limit it to this.