Statiq

The official guide on how to deploy your website to Netlify, which can be found here, explains the required steps:

• Step 1: Add Your New Site. Creating a new site on Netlify is simple.
• Step 2: Link to Your GitHub (or supported version-control tool of choice)
• Step 3: Authorize Netlify.
• Step 4: Select Your Repo.
• Step 5: Configure Your Settings.
• Step 6: Build Your Site.
• Step 7: All Done.

And it’s really as simple as that. The very blog you are exploring at the moment is deployed on Netlify too, and the score is pretty great, as you can see on Test My Site:

The answer is simple - Netlify CMS doesn’t fully support Statiq Web yet. You can read more on the subject in this thread.