minor #1654 [Icons] Update demo URL (yoanbernabeu)

This PR was merged into the 2.x branch.

Discussion
----------

[Icons] Update demo URL

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no <!-- please update src/**/CHANGELOG.md files -->
| Issues        | Fix #... <!-- prefix each issue number with "Fix #", no need to create an issue if none exist, explain below instead -->
| License       | MIT

I think a small mistake has crept into the readme. The link to the UX Icons demo does not seem to be the right one.

Thank you for the work

Commits
-------

b237367 Update demo URL

Author: kbond

src/Icons/README.md

@@ -11,7 +11,7 @@ Renders local and remote SVG icons in your Twig templates.
 <svg viewBox="0 0 24 24" fill="currentColor" class="w-4 h-4"><path fill="currentColor" d="M21 7L9 19l-5.5-5.5l1.41-1.41L9 16.17L19.59 5.59z"/></svg>
 ```
 
-Want a demo? Check out https://ux.symfony.com/ux-icons.
+Want a demo? Check out https://ux.symfony.com/icons.
 
 **This repository is a READ-ONLY sub-tree split**. See
 https://github.com/symfony/ux to create issues or submit pull requests.