Hi @Fernando_Valladares, Welcome to the community! 
This is a needed feature!
I’d like user to upload .pdf for sure 
Based on my knowledge coda has never released something like a roadmap, and various post here from user (who ask for them) and codans (that explain why there is not one) help to understand the situation, in short this gives them more flexibility that helps coda evolve more quickly (but this is not the official answer)