docs(examples): add the UI Cookbook app for the React v15 docs - #3354

docs(examples): add the UI Cookbook app for the React v15 docs#3354

MartinCupela merged 6 commits into

masterGetStream/stream-chat-react:masterfrom

feat/ui-cookbookGetStream/stream-chat-react:feat/ui-cookbookCopy head branch name to clipboard