Add debug message when disabling caching due to text tracks

ios/Video/RCTVideo.m

@@ -460,6 +460,7 @@ static int const RCTVideoUnset = -1;
        *  to bring in the text track code will crash. I suspect this is because the asset hasn't fully loaded.
        * Until this is fixed, we need to bypass caching when text tracks are specified.
        */
+      DebugLog(@"Caching is not supported for uri '%@' because text tracks are not compatible with the cache. Checkout https://github.com/react-native-community/react-native-video/blob/master/docs/caching.md", uri);
       [self playerItemForSourceUsingCache:uri assetOptions:assetOptions withCallback:handler];
       return;
     }