add .csv type support

[zoheirkhonyagar]

Hi, I need .csv type support . Is that possible ?

[Borewit]

It is not straight forward for sure, it is hard to distinct a .csv from an ordinary text file, as there is no signature.

The way comma's are used could indicate it is .csv. Which require a fair amount of records to be able to reliable detect the pattern.

[sindresorhus]

That's also not accounting for that CSV could also be tab-delimited or colon-delimited. There are also multiple ways values could be escaped. The only good way is to actually parse a file as CSV to see if it's valid, and even then you can't be 100% sure until you check the actual results. I don't think CSV detection would be something we could reliably provide. We should document this fact in the readme.