Updated Features (markdown)

Features.md

@@ -16,6 +16,8 @@
     - Use phone speaker instead of headset
   - **Codec2**
     - Set Codec2 mode/speed from 450 up to 3200 bps
+    - Set maximum super frame size in bytes
+      - Multiple Codec2 frames are aggregated into one super frame of size not larger than this value
     - Enable/disable echo/loopback test mode
     - Enable/disable RX/TX recorder
   - **TNC parameters**