Improve Setting up guide

[JOSHIK27]

Is your feature request related to a problem? Please describe.

In addition to exisiting information in readme file, alternative way of starting dev server locally by executing CARE_API=http://127.0.0.1:9000/ npm run dev from the terminal would be much simpler for beginners for connecting front-end with backend.

Describe the solution you'd like
Under this section, include the other way to starting local dev server once the back-end is up and running to connect front-end and backend.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.

[bodhish]

We have added support for CARE_API in .env.