Triple tildes as a separator break Markdown rendering

[sibprogrammer]

Describe the bug
Hard to edit any presentation because triple tildes (used for slides separation) break Markdown rendering. Markdown renderer interprets three tildes as a beginning of code block.

To Reproduce

1. Go to https://github.com/maaslalani/slides/blob/main/examples/slides.md
2. Check the rendered content (made by GitHub's Markdown renderer)

Expected behavior
Triple dashes are used as a slide separator (like in the lookatme)