Displaying data in index.html

I’m new to hugo and I can’t figure out very simple thing. I’m trying to add data to homepage (index.html), but to no avail. In my data folder I have a file called author.json which looks like this:

  "name": "Name",
  "lastname": "Last Name"

And in my index.html I do the following: {{ .Site.Data.author.name }} but nothing is being displayed.

I’m using hugo-boilerplate theme.