Fix typo

wiki/src/support/known_issues.mdwn

 [[!meta title="Known issues"]]
 
-- For issues with graphics cards, see our [[know issues with graphics cards|known_issues/graphics]].
+- For issues with graphics cards, see our [[known issues with graphics cards|known_issues/graphics]].
 - To learn what you can do with Tails, refer to our [[documentation|doc]].
 - For more general questions about Tails, refer to our [[FAQ|support/faq]].