Add Yii2 API controller

[TheAdnan]

• Add a new folder named yii2

• Inside it add the ApiController for Yii2 framework (a couple of tweaks here and there, but generally an easy task)

• Add a README (use the initial README as a template)

[xepozz]

I'll take this task

[xepozz]

Hm.. do I need to move ApiController and README to folder yii2?

[TheAdnan]

Yeah, but keep the README and ApiController for Yii1 in the root folder.

[archlemon]

What would the controller need to do? All the methods described in your Yii1 controller are already covered in Yii2 via yii\rest\ActiveController and yii\rest\Controller