Examine source code of Selection-Clip

{
  "manifest_version": 2,
  "name": "Selection-Clip",
  "description": "Firefox WebExtension for writing selected text to clipboard",
  "version": "1.1resigned1",
  "homepage_url": "https://github.com/yakaas/webextensions-selection-clip",
  "icons": {
    "48": "icons/clipboard-48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content-script.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{f2374fbc-30d1-4fe5-97bd-b8aaae12264c}"
    }
  }
}