fix: markdown example

[CLAassistant]

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[AnsahMohammad]

@wannacu can you describe the fix or share the screenshot

[jpenna]

For clarity:

https://github.com/AppFlowy-IO/AppFlowy-Docs/blob/main/essential-documentation/markdown.md

Maybe better than removing the OR (like in the PR), it could have it out of the code block:

** ** OR __ __