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

src/core/Session.ts

@@ -11,6 +11,7 @@ import Proto from '../proto';
 
 export enum ClientType {
   WEB = 'WEB',
+  KIDS = 'WEB_KIDS',
   MUSIC = 'WEB_REMIX',
   ANDROID = 'ANDROID',
   ANDROID_MUSIC = 'ANDROID_MUSIC',
@@ -45,6 +46,15 @@ export interface Context {
     deviceMake: string;
     deviceModel: string;
     utcOffsetMinutes: number;
+    kidsAppInfo?: {
+      categorySettings: {
+        enabledCategories: string[];
+      };
+      contentSettings: {
+        corpusPreference: string;
+        kidsNoSearchMode: string;
+      };
+    };
   };
   user: {
     enableSafetyMode: boolean;