Inkblotty is one of the many themes offered by Hugo. I discovered, via much trial and error, that this theme expects text files for posts to be in a directory named post (singular). posts (plural) will not do.
Also, the impact of formatting does not appear in the preview on the front page.
UPDATE 2020.07.08: After having trouble deploying my original pages to Netlify while using the Inkblotty theme, I switched to the Notepadium theme.
FURTHER UPDATE: I should add that Inkblotty was not the problem. I had forgotten to change draft: true to draft: false in the heads of my posts.