Examine source code of Playlist

{
  "name": "Playlist",
  "short_name": "Playlist",
  "version": "0.0.9.1",
  "manifest_version": 2,
  "description": "Create a playlist of webpages whether it is for music or videos or just to keep track of what you want to look at.",
  "author": "Sh8dz",
  "icons": {
    "16": "icons/PL16.png",
    "48": "icons/PL48.png",
    "128": "icons/PL128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "playlist@sh8dz.com",
      "strict_min_version": "57.0"
    }
  },
  "applications": {
    "gecko": {
      "id": "playlist@sh8dz.com"
    }
  },
  "browser_action": {
    "default_title": "Playlist",
    "default_popup": "popup/index.html"
  },
  "sidebar_action": {
    "default_title": "Playlist",
    "default_panel": "sidebar/index.html",
    "default_icon": "icons/PL16.png"
  },
  "background": {
    "scripts": [
      "src/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "match_about_blank": true,
      "js": [
        "src/framescript.js"
      ],
      "run_at": "document_start",
      "all_frames": true
    },
    {
      "matches": [
        "<all_urls>"
      ],
      "match_about_blank": true,
      "js": [
        "src/topscript.js"
      ],
      "run_at": "document_end",
      "all_frames": false
    },
    {
      "matches": [
        "<all_urls>"
      ],
      "match_about_blank": true,
      "js": [
        "src/contentscript.js"
      ],
      "run_at": "document_idle",
      "all_frames": true
    }
  ],
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "permissions": [
    "tabs",
    "sessions",
    "http://*/",
    "<all_urls>",
    "storage",
    "unlimitedStorage",
    "notifications",
    "contextMenus"
  ],
  "commands": {
    "enqueue": {
      "suggested_key": {
        "default": "Ctrl+Alt+A",
        "mac": "Command+Alt+A"
      },
      "description": "Adds current page to the current playlist"
    },
    "start": {
      "suggested_key": {
        "default": "Ctrl+Alt+S",
        "mac": "Command+Alt+S"
      },
      "description": "Starts playing or stops running playlist in current tab"
    },
    "startInNewTab": {
      "suggested_key": {
        "default": "Ctrl+Alt+X",
        "mac": "Command+Alt+X"
      },
      "description": "Start playing in new pinned tab"
    },
    "playPause": {
      "suggested_key": {
        "default": "MediaPlayPause"
      },
      "description": "Plays or pauses the media in the last used tab running a playlist"
    },
    "previous": {
      "suggested_key": {
        "default": "MediaPrevTrack"
      },
      "description": "Plays the previous track of the playling playlist in the current tab"
    },
    "next": {
      "suggested_key": {
        "default": "MediaNextTrack"
      },
      "description": "Plays the next track of the playling playlist in the current tab"
    },
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Ctrl+Alt+D",
        "mac": "Command+Alt+D"
      },
      "description": "Display playlist popup"
    },
    "_execute_sidebar_action": {
      "suggested_key": {
        "default": "Ctrl+Alt+B",
        "mac": "Command+Alt+B"
      },
      "description": "Display playlist in side bar"
    },
    "Shuffle": {
      "description": "Plays the playlist in a shuffle order or stop doing so"
    },
    "Loop": {
      "description": "Loops the playlist or stops doing so"
    }
  }
}