What’s the easiest way to add articles to my website without uploading HTML files each time?

The cleanest method might be transitioning your article writing to markdown and using a static site generator like Jekyll. With GitHub Pages support, you could simply create markdown files instead of writing full HTML each time.

If you want to keep things simple, you might try using a full CMS like WordPress. However, if you prefer sticking with GitHub Pages, a static site generator like Jekyll might be a good fit. It lets you write in markdown, which gets converted to HTML automatically.

Consider using a backend system with a database. This way, your site can dynamically fetch content, so there's no need to create a new HTML file each time you want to update or add an article.

For a more hands-on approach, you could continue what you're doing and just automate local uploads with a tool like GitHub CLI. It makes it easier to add new pages without hassle.

There's also the possibility of using Notion as a sort of database to store your content and fetch it directly from there. It can streamline the process without needing to change much in your current setup.