Examine source code of Refined Microsoft Teams

{
  "name": "__MSG_appName__",
  "description": "__MSG_appDescription__",
  "version": "0.3.5",
  "manifest_version": 2,
  "icons": {
    "16": "images/icon-16.png",
    "128": "images/icon-128.png"
  },
  "default_locale": "en",
  "permissions": [
    "http://teams.microsoft.com/_",
    "https://teams.microsoft.com/_"
  ],
  "options_ui": {
    "page": "popup.html"
  },
  "browser_action": {
    "default_title": "Refined Microsoft Teams",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "http://teams.microsoft.com/_",
        "https://teams.microsoft.com/_"
      ],
      "js": [
        "scripts/injector.js",
        "scripts/popup.js"
      ],
      "css": [
        "styles/2-columns.css",
        "styles/bulk-add-team-members.css",
        "styles/multitenant-panel.css"
      ],
      "run_at": "document_end",
      "all_frames": false
    }
  ],
  "background": {
    "scripts": [
      "scripts/background.js"
    ],
    "persistent": true
  },
  "web_accessible_resources": [
    "scripts/multitenant-panel.js",
    "scripts/bulk-add-team-members.js"
  ]
}