They could also learn how the website works, or how markdown works. Not everyone needs to be treated like toddlers. Colleagues can be surprisingly capable if you educate them.
Why should they have to conform to your poor choice of tech? Why would anyone want their content creators use html or limited markdown when we've had competent GUI alternatives for decades now.
Indeed. But I also know lots of people in tech/IT who would straight out refuse to touch Git/Github/Markdown. Some of them might have good reasons. Some do not, but still refuse.
When trying to educate a group of people, it is useful to understand the range of experiences they might have had.
For example, you might ask a question like "How do non-techies edit Jamstack websites?"