This project is about programming a function that returns a line read from a file descriptor
Calling get_next_line function in a loop will then allow you to read the text file one line at a time until the end of it.
Bonus: To be able to manage multiple file descriptors with your get_next_line. For example, if the file descriptors 3, 4 and 5 are accessible for reading, then you can call get_next_line once on 3, once on 4, once again on 3 then once on 5 etc. without losing the reading thread on each of the descriptors.