Examine source code of Slicon

{
  "manifest_version": 2,
  "name": "Slicon",
  "description": "Set icon to your slack channel, and make more accessible for your favorite channel!",
  "version": "0.2.0",
  "content_scripts": [
    {
      "matches": [
        "https://*.slack.com/*"
      ],
      "css": [
        "main.css"
      ],
      "run_at": "document_start"
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "https://*.slack.com/*",
    "webRequest",
    "activeTab",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "57.0"
    }
  },
  "icons": {
    "16": "icon.svg",
    "48": "icon.svg",
    "128": "icon.svg"
  }
}