This PR adds the Strava badge on the homepage next to the other social icons, and updates the content in the Quick Introduction section of about.mdx. Appropriate CSS additions to the main.css stylesheet for the Strava badge.

PR CHECKLIST

• My code follows the style guidelines of this project (variable naming, commenting, copyright, etc.)
• I have performed a self-review of my code
• Changes are clearly highlighted and easy to understand
• I have commented my code, particularly in hard-to-understand areas
• I have meaningful commit messages that explain what was changed/committed
• I have built and locally tested my changes
• My changes generate no new errors or regressions (pending verification)
• I have made corresponding changes to the documentation OR this is N/A
• Documentation accurately reflects the current state of the project OR this is N/A
• I have added tests that prove my fix is effective or that my feature works OR this is N/A
• New and existing unit tests pass locally with my changes OR this is N/A
• Any dependent changes have been merged and published in downstream modules OR this is N/A
• All links are working and correct OR this is N/A
• Spelling and grammar are correct
• I have added the "READY FOR REVIEWS" tag when this PR is ready for reviews