Api docs update (#344)

* API: Add "authorVerified" to VideoObject and /channel/id endpoint
* API: Add "tabs" field to main channel endpoint

docs/api/channels_endpoint.md

@@ -13,6 +13,7 @@ details on the various JSON objects used below.
 	"author": String,
 	"authorId": String,
 	"authorUrl": String,
+	"authorVerified": Boolean,
 	"authorBanners": [
 		// One or more ImageObject
 	],
@@ -29,7 +30,9 @@ details on the various JSON objects used below.
 
     "description": String,
     "descriptionHtml": String,
-	"allowedRegions": [String],
+	"allowedRegions": String[],
+
+	"tabs": String[],
 
 	"latestVideos": [
 		// One or more VideoObject

docs/api/common_types.md

@@ -36,6 +36,7 @@
 	"author": String,
 	"authorId": String,
 	"authorUrl": String,
+	"authorVerified": Boolean,
 
 	"videoThumbnails": [
 		// One or more ThumbnailObject