Update contributing.md with appropriate link to golangci-lint

[echarlesgrasby]

Two small document changes

1. Updated link in contributing.md to point to golangci-lint's website (it was pointing to the website for the pre-commt project).
2. Updated existing warning in README.md regarding auto-generated code. I simply added a Warning admonition command in Markdown to make this more easily stand out to the reader.

• [x] I certify that this PR does not contain any code that has been generated with GitHub Copilot or any other AI-based code generation tool, in accordance with this project's policies.

Description

Basic documentation update to fix a link that redirects the reader to a resource not related to the link itself (goes to pre-commit instead of the link's text: golangci-lint)

Testing done

• How did you test your changes?
  1. Committed my code to my fork of the project, then clicked the link and checked that it routed me to golangci-lint.run from GitHub's markdown viewer.
  2. Also visually verified that the Warning admonition appears in the README.md file
• Does this code require any new tests to be written?
  1. N/A - documentation change only

Additional info

Resolves issue #83

[drmorr0]

@echarlesgrasby thank you!!!