Merge pull request roboflow#996 from roboflow/fix/doc_syntax_fix

doc: 📚 json and csv example code syntax fix

Author: SkalskiP

supervision/detection/tools/csv_sink.py

@@ -42,7 +42,7 @@ class CSVSink:
         csv_sink = sv.CSVSink(<RESULT_CSV_FILE_PATH>)
         frames_generator = sv.get_video_frames_generator(<SOURCE_VIDEO_PATH>)
 
-        with csv_sink:
+        with csv_sink as sink:
             for frame in frames_generator:
                 result = model(frame)[0]
                 detections = sv.Detections.from_ultralytics(result)

supervision/detection/tools/json_sink.py

@@ -32,7 +32,7 @@ class JSONSink:
         json_sink = sv.JSONSink(<RESULT_JSON_FILE_PATH>)
         frames_generator = sv.get_video_frames_generator(<SOURCE_VIDEO_PATH>)
 
-        with json_sink:
+        with json_sink as sink:
             for frame in frames_generator:
                 result = model(frame)[0]
                 detections = sv.Detections.from_ultralytics(result)