README - Improvement and updation for making it more new user friendly

[prasunparijat]

• When I initially explored the repository as a new user, I encountered challenges running the example folder.
• To enhance the user experience and streamline the setup process, I've provided more detailed and explicit instructions.
• This includes clarifying the steps involved in obtaining and setting environment variables, specifically using Google Sign-in as an example.
• By removing unnecessary elements like the dollar sign from commands and offering additional guidance, I aim to boost user confidence and encourage further exploration of the repository.