Add htmlhint file

{

  "attr-lowercase": true,

  "attr-value-double-quotes": true,

  "tag-pair": true,

  "spec-char-escape": true,

  "id-unique": true,

  "src-not-empty": true,

  "attr-no-duplication": true,

  "title-require": true,

  "tagname-lowercase": true,

  "attr-value-not-empty": true,

  "alt-require": true,

  "style-disabled": true,

  "inline-style-disabled": true,

  "space-tab-mixed-disabled": "space",

  "attr-unsafe-chars": true,

  "id-class-ad-disabled": true,

  "inline-script-disabled": true,

  "head-script-disabled": true,

  "csslint": {

    "display-property-grouping": true,

    "known-properties": true

  }

}