Examine source code of Submit to ImageRights

{
  "manifest_version": 2,
  "name": "__MSG_manifest_name__",
  "short_name": "__MSG_manifest_short_name__",
  "version": "1.2.0",
  "description": "__MSG_manifest_description__",
  "author": "__MSG_manifest_author__",
  "homepage_url": "https://www.imagerights.com/",
  "developer": {
    "name": "__MSG_manifest_author__",
    "url": "https://www.imagerights.com/"
  },
  "default_locale": "en",
  "icons": {
    "16": "icons/16.png",
    "20": "icons/20.png",
    "25": "icons/25.png",
    "30": "icons/30.png",
    "32": "icons/32.png",
    "40": "icons/40.png",
    "48": "icons/48.png",
    "76": "icons/76.png",
    "96": "icons/96.png",
    "128": "icons/128.png",
    "270": "icons/270.png"
  },
  "permissions": [
    "activeTab",
    "contextMenus"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "browser_style": true,
    "default_icon": {
      "16": "icons/16.png",
      "20": "icons/20.png",
      "25": "icons/25.png",
      "30": "icons/30.png",
      "32": "icons/32.png",
      "40": "icons/40.png",
      "48": "icons/48.png",
      "76": "icons/76.png",
      "96": "icons/96.png",
      "128": "icons/128.png",
      "270": "icons/270.png"
    },
    "default_title": "__MSG_manifest_default_title__"
  },
  "commands": {
    "_execute_browser_action": {
      "description": "Equivalent to clicking the extension's icon.",
      "suggested_key": {
        "default": "Ctrl+Shift+S"
      }
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "48.0"
    }
  }
}