Use more clear function name

src/j1939_decoder.py

@@ -12,7 +12,7 @@ def get_j1939_mask() -> pl.Expr:
         (pl.col("DLC") <= 8)
     )
 
-def decode_j1939(lf: pl.LazyFrame) -> pl.LazyFrame:
+def decode_j1939_metadata(lf: pl.LazyFrame) -> pl.LazyFrame:
     """
     Decodes J1939 fields and bundles them into a Struct column.
     """
@@ -50,7 +50,7 @@ if __name__ == "__main__":
     lf = pl.scan_parquet(args.input_parquet)
 
     print("[*] Decoding J1939 IDs into a nested Struct column")
-    lf_decoded = decode_j1939(lf)
+    lf_decoded = decode_j1939_metadata(lf)
 
     print(f"[*] Saving decoded data to {args.output_parquet}")
     lf_decoded.sink_parquet(args.output_parquet)