Add Korean and Hindi

[NirantK]

As per discussion in #79, adding prelim sections for Hindi and Korean, YAMLized.

• Next: Will expand Hindi and add other languages if this looks okay to both of us.
• Help: Adding 'score='BLUE' to the markdown does not add machine translation metrics to HTML. Any hints?
• Request: Please squash commits when merging

---

@sebastianruder
Now that I've tried the YML versions, I am all the more in favor of human-readable Markdowns.

Pros:

• Easier trend spotting in performance improvements

Cons:

• Hard for contributors, e.g. I can't spot HTML omissions without setting up Jekyll locally
• Github Repo becomes useless for readers, relying exclusively on nlpsota.com

[sebastianruder]

Hi @NirantK,

Great, thanks a lot!
Re help: You need to specify scores instead of score and the metric needs to have the same name as in the Table (see my commit here).
Re squashing commits: Cool. I actually wasn't aware of this feature. Thanks for pointing me to it. :)

Re YAML: Fair point and I see where you're coming from. At the moment, I think the benefit of YAML is indeed limited. Let's discuss this in a separate issue.

[NirantK]

1. Thanks for the 'scores' commit and tip!
2. Sure, let's discuss that separately. Please squash and merge this so that I can start pointing people working on Hindi to here :)

[sebastianruder]

Sure. I think you just need to update the scores yourself unfortunately as pushing my commit didn't add it to this one, but created a separate branch. :-/ The scores for Korean also still need to be fixed.

[NirantK]

Got it, closing this in favour of a new PR with your commit