arecord: add example list audio devices and intractive interface (#4530)

pages/linux/arecord.md

@@ -14,3 +14,11 @@
 - Record a snippet and save it as mp3 (finish with Ctrl-C when done):
 
 `arecord -vv --format=cd --file-type raw | lame -r - {{path/to/file.mp3}}`
+
+- List all sound cards and digital audio devices:
+
+`arecord --list-devices`
+
+- Allow interactive interface (e.g. use space-bar or enter to play or pause):
+
+`arecord --interactive`