Add Spoken Language Understanding

[Edward Qian]

I wonder if SLU can be added to the English section and maybe the chinese section.

It's shares similarities between sentiment analysis and NER, but there are couple datasets out there (ATIS. SNIPS), and some research. Plus there has already been a bit of a start from https://github.com/zhenwenzhang/Slot_Filling, there are some newer SOTA missing.

I could start the PR for it.

[Sebastian Ruder]

Sure, that'd be great! :)