GH Pages: fix website after markdown tweaks

* The `license` URL needs to be an absolute URL for it to also work from within the webpage.
* The matching of the badges broke due to the reference links. Let's just keep the links for the relevant badges inline to prevent this.

Author: jrfnl

.remarkrc

@@ -40,7 +40,6 @@
     "remark-lint-list-item-punctuation",
     "remark-lint-match-punctuation",
     "remark-lint-no-hr-after-heading",
-    "remark-lint-are-links-valid-duplicate",
     "remark-validate-links"
   ]
 }

README.md

@@ -2,8 +2,8 @@
 
 <div aria-hidden="true">
 
-[![Latest Stable Version](https://img.shields.io/packagist/v/phpcsstandards/phpcsdevtools?label=stable)][phpcsdevtools-packagist]
-[![Release Date of the Latest Version](https://img.shields.io/github/release-date/PHPCSStandards/PHPCSDevTools.svg?maxAge=1800)][phpcsdevtools-releases]
+[![Latest Stable Version](https://img.shields.io/packagist/v/phpcsstandards/phpcsdevtools?label=stable)](https://packagist.org/packages/phpcsstandards/phpcsdevtools)
+[![Release Date of the Latest Version](https://img.shields.io/github/release-date/PHPCSStandards/PHPCSDevTools.svg?maxAge=1800)](https://github.com/PHPCSStandards/PHPCSDevTools/releases)
 [![Changelog](https://img.shields.io/github/v/release/PHPCSStandards/PHPCSDevTools?label=Changelog&sort=semver)](https://github.com/PHPCSStandards/PHPCSDevTools/blob/stable/CHANGELOG.md)
 :construction:
 [![Latest Unstable Version](https://img.shields.io/badge/unstable-dev--develop-e68718.svg?maxAge=2419200)](https://packagist.org/packages/phpcsstandards/phpcsdevtools#dev-develop)
@@ -234,7 +234,7 @@ If unsure whether the changes you are proposing would be welcome, open an issue
 
 ## License
 
-This code is released under the [GNU Lesser General Public License (LGPLv3)](LICENSE).
+This code is released under the [GNU Lesser General Public License (LGPLv3)](https://github.com/PHPCSStandards/PHPCSDevTools/LICENSE).
 
 
 [phpcsdevtools-packagist]: https://packagist.org/packages/phpcsstandards/phpcsdevtools