Open Project in Browser Tab

## Description
As a developer, I want to have this process automated.

On `yarn start`, I want project URL to be opened in browser window under specific conditions.
- Open URL in Browser (i.e. default/mentioned)
- In specified mode of browser (i.e. incognito/guest)
- Above configurations can be customized for each developer (preferably via .env file)

## Implementation Details
Configure `dotenv` dependency.
Configure browser options in `webpack.config.js` via variables set in `.env` file.

Start with the yarn start entry point and webpack.config.js, then review the requested dotenv configuration and browser options described in the issue. Done means the project URL opens under the selected browser and mode, with those settings customizable per developer through .env.

Written by the indexing model from the issue text.