Add info to readme with comparison with infer

[qarmin]

No description provided.

[mmalecot]

I don't like to compare my projects with those of others, because I wouldn't be objective, so I let the community do it if it's necessary.

The only thing I can say is that file-format detects many more file formats than infer but not only serves as a detection tool but also provides a lot of information about file formats such as their kind, name, extension and so on. On the other hand, infer mights be lighter and faster if you need to detect classic file formats.