Document API / backend endpoints in README

[Dippp10]

@Raju KUMAR RAJA ji, The README mostly describes frontend features (React, Tailwind, Firebase). There is little to no documentation on how the backend / Firebase functions are laid out, what endpoints exist, and how to use them. Add a section (or link) that lists the API endpoints (or Firebase functions), their request & response formats, authentication requirements, etc.

[Dippp10]

@Raju KUMAR RAJA ji, i have created above issue number 117..... Do assign GSSoC'2025 label and level 1 label to it.... Do assign mentors to it....do assign above issue to me