Customizing Chromebook - Word or Docs only

I'm a writer with the attention span of a young gerbil. I've used plenty of distraction-reducing apps etc on my MacBook; the problem is that when my ADHD kicks in, I'll go to pretty much any length to circumvent them. I'm looking for a way to write/work that doesn't just reduce distractions but preempts them altogether. More specifically:

I'm wondering if it's possible to somehow customize a Chromebook to run one app and one app only (specifically Microsoft Word or Google Docs). In a perfect world, it wouldn't even give me the option to click out of the app to a desktop or a home screen: in other words, it'd effectively be a typewriter that just so happens to have a screen display and hard drive storage. No internet browser; hell, no internet connectivity.

I know zero about Chromebooks and ChromeOS, so forgive me if I'm asking a question to which the answer is flagrantly no, you idiot, and also just be an adult and learn how to self-regulate your attention span. But if someone can help me out with this I'd be grateful. I've been invited to a weeklong writers' residency next month and in a perfect world I'd leave my MacBook (a little carnival of distractions) at home