Examine source code of ScrollKeeper for browsers

{
  "name": "ScrollKeeper for browsers",
  "description": "Save and jump to scroll positions with hotkeys, titles, and a visual list of bookmarks in the popup.",
  "version": "1.0.2",
  "manifest_version": 3,
  "short_name": "ScrollKeeper",
  "author": "LaneZero",
  "browser_specific_settings": {
    "gecko": {
      "id": "scrollkeeper@lanezero.dev",
      "strict_min_version": "109.0"
    }
  },
  "permissions": [
    "activeTab",
    "storage",
    "contextMenus",
    "scripting"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    },
    "default_popup": "popup.html",
    "default_title": "ScrollKeeper"
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "styles.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "commands": {
    "save_bookmark_1": {
      "suggested_key": {
        "default": "Ctrl+1"
      },
      "description": "Save bookmark to slot 1"
    },
    "save_bookmark_2": {
      "suggested_key": {
        "default": "Ctrl+2"
      },
      "description": "Save bookmark to slot 2"
    },
    "save_bookmark_3": {
      "suggested_key": {
        "default": "Ctrl+3"
      },
      "description": "Save bookmark to slot 3"
    },
    "save_bookmark_4": {
      "suggested_key": {
        "default": "Ctrl+4"
      },
      "description": "Save bookmark to slot 4"
    },
    "save_bookmark_5": {
      "suggested_key": {
        "default": "Ctrl+5"
      },
      "description": "Save bookmark to slot 5"
    },
    "save_bookmark_6": {
      "suggested_key": {
        "default": "Ctrl+6"
      },
      "description": "Save bookmark to slot 6"
    },
    "save_bookmark_7": {
      "suggested_key": {
        "default": "Ctrl+7"
      },
      "description": "Save bookmark to slot 7"
    },
    "save_bookmark_8": {
      "suggested_key": {
        "default": "Ctrl+8"
      },
      "description": "Save bookmark to slot 8"
    },
    "save_bookmark_9": {
      "suggested_key": {
        "default": "Ctrl+9"
      },
      "description": "Save bookmark to slot 9"
    },
    "jump_to_bookmark_1": {
      "suggested_key": {
        "default": "Alt+1"
      },
      "description": "Jump to bookmark 1"
    },
    "jump_to_bookmark_2": {
      "suggested_key": {
        "default": "Alt+2"
      },
      "description": "Jump to bookmark 2"
    },
    "jump_to_bookmark_3": {
      "suggested_key": {
        "default": "Alt+3"
      },
      "description": "Jump to bookmark 3"
    },
    "jump_to_bookmark_4": {
      "suggested_key": {
        "default": "Alt+4"
      },
      "description": "Jump to bookmark 4"
    },
    "jump_to_bookmark_5": {
      "suggested_key": {
        "default": "Alt+5"
      },
      "description": "Jump to bookmark 5"
    },
    "jump_to_bookmark_6": {
      "suggested_key": {
        "default": "Alt+6"
      },
      "description": "Jump to bookmark 6"
    },
    "jump_to_bookmark_7": {
      "suggested_key": {
        "default": "Alt+7"
      },
      "description": "Jump to bookmark 7"
    },
    "jump_to_bookmark_8": {
      "suggested_key": {
        "default": "Alt+8"
      },
      "description": "Jump to bookmark 8"
    },
    "jump_to_bookmark_9": {
      "suggested_key": {
        "default": "Alt+9"
      },
      "description": "Jump to bookmark 9"
    },
    "go_back": {
      "suggested_key": {
        "default": "Ctrl+0"
      },
      "description": "Go back to previous position"
    },
    "toggle_titles": {
      "suggested_key": {
        "default": "Ctrl+Q"
      },
      "description": "Toggle all titles"
    },
    "toggle_visibility": {
      "suggested_key": {
        "default": "Ctrl+Alt+V"
      },
      "description": "Toggle bookmark visibility"
    }
  }
}