Examine source code of MCM Emotes

{
  "manifest_version": 2,
  "default_locale": "en",
  "name": "MCM Emotes",
  "version": "1.1.0",
  "author": "Ember",
  "description": "Adds more emotes to MC-Market shoutbox",
  "icons": {
    "16": "icons/icon-16.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.mc-market.org/*"
      ],
      "all_frames": true,
      "run_at": "document_end",
      "js": [
        "dist/src/background.js"
      ]
    }
  ],
  "page_action": {
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png"
    },
    "default_title": "MCM Emotes"
  },
  "permissions": [
    "https://www.mc-market.org/*",
    "<all_urls>"
  ]
}