[web-php] PR #522: Use the PHP logo by Levi Morrison as favicon

Pull Request: https://github.com/php/web-php/pull/522 Author: lhsazevedo ## Intro Looking at the reactions on my proposal at #344, I guess some of you might have liked it:   The logo is one used on php.net, created by Levi Morrison and available at https://www.php.net/download-logos.php. I've used the #4f5b93 blue from the PHP 8 release page as background. ## Formats It will be available in the following formats: - Traditional .ICO icon with both 16x16 and 32x32 variants. - PNGs in 16x16, 32x32 and 196x196px. - SVG Many websites offer icons for mobile home screen shortcuts as well (apple-touch-icon/webmanifest). I've intentionally left them out in this patch, but we could add them later if needed. The [Real Favicon Generator FAQ](https://realfavicongenerator.net/faq) and the [How to Favicon in 2022](https://evilmartians.com/chronicles/how-to-favicon-in-2021-six-files-that-fit-most-needs) are great resources for this topic. ## Cache refresh I've included a query string parameter v=2 in the links to force a refresh in the visitors web browsers. ## Project files Visit https://github.com/lhsazevedo/web-php-favicon for the Inkscape project.