This closes #234.

When I have a list of items (could be objects as well) in the json data file.

[
    "item1", "item2","item3"
]

Now when trying to use them in a loop like

## for item in .
{{ item }}
## endfor

Consideration: Is "." appropriate to refer the root document? If not, I'll make another pull request.
Note: This is ad-hoc fix. "." cannot be set as the second or later argument. It may be fixed by #247 though I have not confirmed it.