Examine source code of Mel to :mel:

{
  "name": "Mel to :mel:",
  "manifest_version": 2,
  "version": "0.2resigned1",
  "description": "Replaces instances of \"mel\" with a weary-faced bread icon.",
  "icons": {},
  "background": {
    "scripts": [
      "bg.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "mel.js"
      ]
    }
  ],
  "permissions": [
    "http://*/*",
    "https://*/*",
    "activeTab",
    "contextMenus"
  ],
  "browser_action": {
    "default_title": "",
    "default_icon": "images/mel.png"
  },
  "web_accessible_resources": [
    "images/mel.png"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{f5f1ca61-9d03-4bb7-b5eb-9d6c97056313}"
    }
  }
}