README.md "Quick Introduction" is broken

[eritain]

Describe the bug
Documentation directs brand-new users to download task data to one place and read it from another.

To Reproduce
Follow the "Python version" quick introduction instructions as seen in the README. In particular,

downloader.download_data(["mrpc"], "/content/data")

do that line as written, if you even have write permission on your root dir. If you don't, use some approximation of /content/data that you can write to, and wonder if you're breaking something. You are breaking something, but not because you deviated too far from /content/data.

Continue with the rest of the instructions. tokenize_and_cache.py will die because the MRPC data aren't in ${EXP_DIR}/tasks.

Expected behavior
Jiant fine-tunes a pretrained RoBERTa on MRPC.

Additional context
This is not the only way to break tokenize_and_cache from the downloader, but a separate issue will be filed on that.

[zphang]

Hi @eritain, thanks so much for your feedback. I've updated the documentation with #1282.