README: fix formatting

Author: Gnurou

README.md

@@ -63,8 +63,7 @@ Implemented devices are:
   here for reference and testing purposes.
 - A proxy device for host V4L2 devices, i.e. a device allowing to expose a host
   V4L2 device to the guest almost as-is (`v4l2_device_proxy.rs`).
-
-* A FFmpeg-based video decoder device as a separate crate in
+- A FFmpeg-based video decoder device as a separate crate in
   `extras/ffmpeg-decoder`.
 
 ## Virtio device ID