Fix Icon documentation

[Jeremy-Walton]

Why?

The icon descriptions were lacking and some of the examples were not pointing to the right files.

What Changed

• Fix the icon paths in the documentation
• Update the feather and lucid icon addon descriptions

Quality Assurance

• Have you tagged the PR with the correct labels?
• Have you validated the changes?
  • Have you run linters? (yarn sanity-check)
  • Have you run prettier?
  • Have you tried building the css?
  • Have you tried building storybook?
• [ ] Have you updated any usage of changed tokens?
• [ ] Did you add a component?
  • [ ] Have you added it to the dependency graph?
  • [ ] Have you added it to the docs?
• [ ] Did you update a component?
  • [ ] Have you updated the dependency graph?
  • [ ] Have you updated the docs?
• [ ] Do you need to update the package version?
  • Planning on this being part of v2.3.0

Screenshots