Introduce config file for CSS

[vcpablo]

{
  "css": {
    "dir": "path/to/css/files",
    "files": [
      "file.css",
      "file2.css"
    ]
  },
  "js": {
    "dir": "path/to/js/files",
    "files": [
      "file.js",
      "file2.js"
    ]
  },
  "widgets": {
    "label": {
      "wrapper": "div class=\"class 1 class 2\"",
      "tag": "ion-label class=\"class1 class2\"",
    }
  },
  "externalLinks": [
    "http://cdn/css.css"
  ],
  "externalScripts": [
    "https://cdn/script.js"
  ]
}