Add ffmpeg example (#61)

ffmpeg-examples/README.md

@@ -0,0 +1,16 @@
+# Introduction
+
+You can use `sherpa-onnx-ffmpeg` to decode a wav, mp3, or even a URL.
+
+See <https://github.com/ossrs/srs>
+for more supported formats and protocols, e.g.,
+RTMP/WebRTC/HLS/HTTP-FLV/SRT/MPEG-DASH/GB28181.
+
+
+## How to use
+
+Please have a look at
+
+```
+./run.sh
+```