Add availability endpoint for finding free slots

Implement slot-finding algorithm with DTOs, service layer, and core time range logic

Add logic for Add/Update/Remove event participants in EventParticipantService

Add IEventParticipantService and EventParticipantService for Managing Event Participants

Complete EventService (Get, Update, Delete) and Implement EventsController Endpoints

Add Event DTOs and initial EventService implementation with CreateEventAsync

Add JWT-based login endpoint and authentication service

Implement UsersController with CRUD endpoints and API versioning

Extend User entity and DTOs with email, firstName, and lastName

Implement UserService with password hashing and MongoDB logic

Add DTOs for user registration, update, and response

Define domain entities and configure MongoDB connection

Add project files.

Add .gitattributes and .gitignore.