Switch tabs to spaces and fix a minor docs issue

.stylelintrc.json

@@ -7,7 +7,7 @@
     ],
     "rules": {
         "font-family-no-missing-generic-family-keyword": null,
-		"no-descending-specificity": null,
-		"block-no-empty": null
+        "no-descending-specificity": null,
+        "block-no-empty": null
     }
 }

.travis.yml

@@ -52,7 +52,7 @@ script:
   - composer validate --no-check-all --strict
 
   # Search for PHP syntax errors using PHP Parallel Lint.
-  # https://github.com/php-parallel-lint/PHP-Parallel-Lint
+  # @link https://github.com/php-parallel-lint/PHP-Parallel-Lint
   - composer lint:php
 
   # Check the PHP files with the coding standards documented in the phpcs.xml.dist file.