This was true once, but not anymore.
You can uninstall the Hyde theme plug-in after you’ve installed the theme available on GitHub. And I agree with you that themes and plug-ins are a bit confusing. I think the UI and naming of things need to be tweaked some by @manton.
Here’s a quick guide. I assume your current enabled theme is Hyde.
- Navigate to Design > Edit Custom Themes.
- The next step is confusing, so read it closely.
- Hit the New Plug-in button. (Yeah, I know, weird.)
- Give the GitHub theme a Title and provide the Clone URL. Also, make sure you choose the correct Site in the dropdown if you have more than one blog hosted on Micro.blog.
- Tap the Add plug-in button.
- Now, navigate to Plug-ins and hit the Uninstall button next to the Hyde theme.
- There are no more steps; your GitHub theme should be installed and enabled now.