rfkill: add page (#2502)

pages/linux/rfkill.md

@@ -0,0 +1,23 @@
+# rfkill
+
+> Enable and disable wireless devices.
+
+- List devices:
+
+`rfkill`
+
+- Filter by columns:
+
+`rfkill -o {{ID,TYPE,DEVICE}}`
+
+- Block devices by type (e.g. bluetooth, wlan):
+
+`rfkill block {{bluetooth}}`
+
+- Unblock devices by type (e.g. bluetooth, wlan):
+
+`rfkill unblock {{wlan}}`
+
+- Output in JSON format:
+
+`rfkill -J`