Fix broken karpenter doc links

[cheeseandcereal]

Description

Fixes the broken links in the karpenter guide.

Longer term, the guide should be refreshed with a newer (v1.0.0+) version of karpenter, but for now, just updating to fix the existing links.

Checklist

• Added tests that cover your change (if possible)
• Added/modified documentation as required (such as the README.md, or the userdocs directory)
• Manually tested
• Made sure the title of the PR is a good description that can go into the release notes
• (Core team) Added labels for change area (e.g. area/nodegroup) and kind (e.g. kind/improvement)

BONUS POINTS checklist: complete for good vibes and maybe prizes?! 🤯

• Backfilled missing tests for code in same general area 🎉
• Refactored something and made the world a better place 🌟