feat(yt): add getGuide()

[patrickkfkan]

Add support for fetching YouTube's content guide, contents of which you will find in the left sidebar of YT website:

Usage

const guide = await youtube.getGuide();

// guide.contents:
[
    {
      "type": "GuideSection",
      "items": [
        {
          "type": "GuideEntry",
          "title": {
            "text": "Home"
          },
          "endpoint": {
            "type": "NavigationEndpoint",
            "payload": {
              "browseId": "FEwhat_to_watch"
            },
            "metadata": {
              "url": "/",
              "page_type": "WEB_PAGE_TYPE_BROWSE",
              "api_url": "browse"
            }
          },
          "icon_type": "WHAT_TO_WATCH",
          "is_primary": true
        }
        ...
      ]
    }
    ...
]

[LuanRT]

Looks good. Only thing I think should be added is a getter for the private page prop in the Guide class. This way, users can get the original data and parse however they want.

[patrickkfkan]

Agree. Added.

[LuanRT]

Awesome, merging now. And as always, thank you!