Examine source code of Feedly Subscribe Button

{
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "page_action": {
    "default_icon": "img/icon.svg",
    "default_title": "Subscribe in Feedly",
    "default_popup": "popup.html",
    "browser_style": true
  },
  "content_scripts": [
    {
      "js": [
        "js/sniff_common.js",
        "js/doc_start.js"
      ],
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "run_at": "document_start"
    },
    {
      "js": [
        "js/sniff_common.js",
        "js/feed_finder.js"
      ],
      "matches": [
        "http://*/*",
        "https://*/*"
      ]
    }
  ],
  "description": "Easily Subscribe RSS and Atom Feeds to Feedly.",
  "homepage_url": "https://browsernative.com/feedly-chrome-extension/",
  "icons": {
    "128": "img/128.png"
  },
  "manifest_version": 2,
  "name": "Feedly Subscribe Button",
  "version": "0.10.0",
  "permissions": [
    "tabs",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{a8ffd15d-67d0-427f-80ad-07a7d76431e1}"
    }
  }
}