What is doc as code? Doc as code is basically two things. One, it's creating documentation with the same tools as you would use to create code. Two, it's using similar methods of creating, versioning, and publishing documentation as you would with code.
What do I think about this? Short answer is context. If you're creating or editing material in a software environment that uses Agile methodology, then you should doc as code. Otherwise, I wouldn't worry about it. If you're in this context, I'll give you a few, brief reasons why you should doc as code.