Update readme.md

[yujonglee]

Add new theme.

[pr-code-reviewer[bot]]

:wave: Hi there!

1. Ensure consistency in formatting by aligning the added line with the existing list items.
2. Provide a brief description for the new theme [@getcanary/docusaurus-theme-search-pagefind].
3. Consider adding more context or usage information for better understanding.

The description could be more helpful.

_{^{Automatically generated with the help of gpt-3.5-turbo. Feedback? Please don't hesitate to drop me an email at [email protected].}}

[webbertakken]

@yujonglee thanks for your PR. I missed it before and only just now see it.

I'm happy to merge this, but I've noticed that one of the links is broken. Once the link is fixed I'll add it.

[webbertakken]

@yujonglee any chance you could fix the url?