chore: clarify archive URL phrasing in README

Updated the wording for archive URL references in the README to improve clarity. This ensures contributors can more easily understand how to document their participation.

(This commit message was AI-generated.)

Signed-off-by: Jens Oliver Meiert <jens@meiert.com>

Author: j9t

README.md

@@ -4,7 +4,7 @@
 
 If you’re participating, add or update a [file in participants](https://github.com/css-naked-day/css-naked-day.github.io/tree/issues/160-refactor-eleventy/_src/_data/participants)!
 
-If you have been participating and are not listed, feel free to make a Pull Request and give us reasonable clues. A link to the [Web archive](https://web.archive.org/web/https://css-naked-day.org/) is always welcome, but you might also point to articles or online mentions of your participation.
+If you have been participating and are not listed, feel free to make a pull request and give us reasonable clues. A link to [an archive URL documenting your participation](https://web.archive.org/) is ideal, but you might also point to articles or online mentions of your participation.
 
 Welcome to CSS Naked Day!