Add XML support for PHP_CodeSniffer ruleset file

[shivapoudel]

Ref: https://github.com/squizlabs/PHP_CodeSniffer/wiki/Advanced-Usage#using-a-default-configuration-file

[shivapoudel]

Closes #1092

[PKief]

Wouldn't it make more sense to apply the XML file icon for all file names ending with .xml.dist? If yes, you could add this pattern to the fileExtensions-Array of the XML file icon.

We could also think about a complete new icon for all file names ending with .dist.

[shivapoudel]

@PKief Did you mean this way?

    {
      name: 'xml',
      fileExtensions: [
        'xml',
        'plist',
        'xsd',
        'dtd',
        'xsl',
        'xslt',
        'resx',
        'iml',
        'xquery',
        'tmLanguage',
        'manifest',
        'project',
        '.xml.dist', // Can  `xml.dist` be used or not?
      ],
      fileNames: ['.htaccess'],
    },

Both yml.dist and xml.dist are often configuration files and we used both in our projects.

[PKief]

Thanks looks good, but please take a look at my comments.

[shivapoudel]

Fixed 👍

[PKief]

Thanks, good additions!