Summer Gram

Further work on #24

[Documentation] - Add documentation for each file

1

Currently, the repo does not have any documentation for the source codes. It is better to create documentation for each file. - [ ] `view` source code - [ ]...

refactor(users): Move hardcoded email subjects to constants

12

## Type of Change - [ ] Bugfix - [ ] New feature - [ ] Enhancement - [x] Refactoring - [ ] Dependency updates - [ ] Documentation -...