Add 'liveNow' to /api/v1/channels

src/invidious.cr

@@ -2540,6 +2540,7 @@ get "/api/v1/channels/:ucid" do |env|
               json.field "published", video.published.to_unix
               json.field "publishedText", "#{recode_date(video.published)} ago"
               json.field "lengthSeconds", video.length_seconds
+              json.field "liveNow", video.live_now
               json.field "paid", video.paid
               json.field "premium", video.premium
             end