feat: add ChannelRss

- add documentation
- small model refactor: rename player VideoPlayerDetails.thumbnails to thumbnail

testfiles/player_model/multilanguage.json

@@ -4,7 +4,7 @@
     "title": "100 Girls Vs 100 Boys For $500,000",
     "description": "Giving away $25k on Current! Sign up and use my code “BEAST250” for a chance to win*: https://www.current.com/beast250\n\nSUBSCRIBE OR I TAKE YOUR DOG\n╔═╦╗╔╦╗╔═╦═╦╦╦╦╗╔═╗\n║╚╣║║║╚╣╚╣╔╣╔╣║╚╣═╣ \n╠╗║╚╝║║╠╗║╚╣║║║║║═╣\n╚═╩══╩═╩═╩═╩╝╚╩═╩═╝\n\n----------------------------------------------------------------\nfollow all of these or i will kick you\n• TikTok - https://www.tiktok.com/@mrbeast\n• Twitter - https://twitter.com/MrBeast\n• Instagram - https://www.instagram.com/mrbeast\n• Facebook - https://www.facebook.com/MrBeast6000/\n• Official Merch  - https://www.shopmrbeast.com/\n• Beast Philanthropy - https://www.beastphilanthropy.org/\n\nText me @ +1 (917) 259-6364\nI'm Hiring! - https://www.mrbeastjobs.com/\nOrder a beast burger 🍔 -  https://mrbeastburger.com\nChocolate 🍫 Win a Tesla or be in a MrBeast video - Buy now ▸ https://feastables.com\n-----------------------------------------------------------------—\n\nCurrent is a financial technology company, not a bank. Banking services provided by Choice Financial Group, Member FDIC. The Current Visa Debit Card is issued by Choice Financial Group pursuant to a license from Visa U.S.A. Inc. and may be used everywhere Visa debit cards are accepted.\n\n*NO PURCHASE OR PAYMENT NECESSARY TO ENTER OR WIN. Open to legal residents of the 50 U.S./D.C., age 18+ (19+ in AL and NE, 21+ in MS). Void outside the 50 U.S./D.C. and where prohibited. Sweepstakes starts at 12:00:01 AM ET on 7/9/22; ends at 11:59:59 PM ET on 10/9/22. Odds of winning will depend upon the number of eligible entries received. For full Official Rules and how to enter without becoming a Current member, visit https://www.current.com/beast250. Sponsor: Finco Services, Inc. d/b/a Current, 30 Cooper Square, Floor 4, New York, NY 10003.",
     "length": 1013,
-    "thumbnails": [
+    "thumbnail": [
       {
         "url": "https://i.ytimg.com/vi/tVWWp1PqDus/hqdefault.jpg?sqp=-oaymwEbCKgBEF5IVfKriqkDDggBFQAAiEIYAXABwAEG&rs=AOn4CLBg0pFmrd-KeoxX0Hb_lF9mvekfsw",
         "width": 168,