Add FreebaseQA dataset
Hi ! It looks like this PR contains changes about other datasets than freebase_qa such as DuoRC.

Can you remove these changes please ? Hi @lhoestq,

I think this happened because of rebasing. I'm unable to remove the duorc commit from the branch.  GEM, Arabic sarcasm datasets are also there. I can't see any merge conflicts, however. Before commiting I always rebase (shouldn't have done that).
Can you explain what is to be done? Should I create a clean PR? Hi @gchhablani 
I think you can simply create another branch and another PR.

If I understand correctly the github diff is messed up because you rebased instead of merge.
Rebasing is supposed to be used only before pushing the branch the first time, or github messes up the diff.
If you want to include changes from master on a branch that is already push you need to use git merge. Thanks @lhoestq.

I understand the issue now. I missed the instructions on the template. Sorry for bothering you unnecessarily, I'm pretty new to contributing on GitHub. I'll make a fresh PR.
 No problem, I'm not a big fan of this weird behavior tbh.
Thanks for making a new PR @lhoestq Haha, well, it's not as weird as not reading the [instructions](https://github.com/huggingface/datasets/blob/master/ADD_NEW_DATASET.md#open-a-pull-request-on-the-main-huggingface-repo-and-share-your-work).
Also, I'm enjoying adding new datasets so it's all cool :)
Adding FreebaseQA dataset suggested in PR #1435 with minor edits. Also closes that PR.
Requesting @lhoestq to review.