Please add contribution guidelines

[programmer290399]

I would really love to contribute papers to this repository , so It'd be really helpful if the repo had clear contribution guidelines which I couldn't find. Please add a section mentioning the guidelines in the readme. 🙂

[AakashKumarNain]

Contributions in this case is really hard. For example, if you submit a paper with annotations, I need to read the paper as well the annotations to make sure that the interpretation is correct, which sadly I can't do atm. Though I am looking for some other ways of contributions and will update them here if they seem feasible options.