Update README.md

[MarkusSagen]

Motivation and Context

Fixes markdown formatting not displayed correctly in Github

How has this been tested?

Checklist

• [X] Opened this PR as a 'Draft Pull Request' if it is work-in-progress
• [X] Assigned myself to the PR
• [X] Added tests to cover my changes

[astrojuanlu]

I'm re-running the CI but I suspect these failures are legitimate (although not from this PR obviously)

[astrojuanlu]

Cherry-picking this on gh-122 for simplicity, thanks @MarkusSagen!