Remove unused pathname and structure references from equality concept

Programming Common Lisp
1

Hi everyone,

I opened this pull request to address issue #467.

GitHub PR:

What I changed

  • Removed the outdated pathname description and example from concepts/equality/about.md.
  • Removed the outdated structure description and example from concepts/equality/about.md.
  • Removed the outdated structure description and example from concepts/equality/introduction.md.

The issue mentioned that these references are no longer used by the equality concept/exercise, so I removed them to keep the documentation consistent.

Iā€™d appreciate any feedback. Thank you!