python : add local file saving example (#123)

Added python example showing how to save .wav file locally without using HTTP service using wave & numpy libraries.

examples/ggwave-to-file/ggwave-to-file-local.py

@@ -0,0 +1,24 @@
+import ggwave
+import wave
+import numpy as np
+
+# Parameters
+volume_ = 20
+sample_rate_ = 48000
+filename = "output.wav"
+
+# Generate audio waveform for string "hello python"
+waveform = ggwave.encode("hello python", protocolId=5, volume=volume_)
+
+# Convert byte data into float32
+waveform_float32 = np.frombuffer(waveform, dtype=np.float32)
+
+# Normalize the float32 data to the range of int16
+waveform_int16 = np.int16(waveform_float32 * 32767)
+
+# Save the waveform to a .wav file
+with wave.open(filename, "wb") as wf:
+    wf.setnchannels(1)                  # mono audio
+    wf.setsampwidth(2)                  # 2 bytes per sample (16-bit PCM)
+    wf.setframerate(sample_rate_)       # sample rate
+    wf.writeframes(waveform_int16.tobytes())  # write the waveform as bytes