Fix speaker rendered throughout paragraph

Each sentence or 'segment' in whisper would be preceded by a [speaker]
notation. This commit fixes that to only include the speaker in front
of a larger group (since a new speaker would start a new diarization
group this will always work).

verbanote/process.py

@@ -72,10 +72,11 @@ def output_txt(diarized_groups: list, transcription_path: Path) -> TxtTranscript
 
         if captions:
             speaker = g[0].split()[-1]
-
+            
+            txt.append(f"[{speaker}] ")
             for c in captions:
-                txt.append(f"[{speaker}] {c['text']}\n")
-        txt.append("\n")
+                txt.append(f"{c['text']}")
+            txt.append("\n\n")
 
     output = "".join(txt)
     fname = Path.joinpath(transcription_path, "transcription_result.txt")