feat: add support for YouTube Kids (#291)

* dev: add `WEB_KIDS` innertube client

* refactor: move DASH manifest stuff out of `VideoInfo`
This makes it easier to use these functions elsewhere.

* feat(ytkids): add `Kids#getInfo()` & `Kids#search()`

* feat: add `Innertube#kids.getHomeFeed()`

* docs: add YouTube Kids API ref

* docs: fix typo

* docs: fix yet another typo

* docs: update YouTube Music API ref
Unrelated but required to reflect changes made to the DASH manifest generation functions

* chore: lint

* chore: add tests

* feat: include `captions` in `VideoInfo`

* chore: fix tests

test/constants.ts

@@ -22,6 +22,10 @@ export const VIDEOS = [
   {
     ID: 'jfKfPfyJRdk',
     QUERY: 'live video'
+  },
+  {
+    ID: 'juN8qEgLScw',
+    QUERY: 'Galapagos Tortoise Can\'t Get Enough Watermelon'
   }
 ];