Documentation: Add FAQ entry

Documentation/faq/index.rst

@@ -0,0 +1,40 @@
+.. todo::
+  Create new subsections as needed.
+
+===
+FAQ
+===
+
+NSH Tricks
+==========
+
+How to interrupt an NSH Application using Ctrl^C ?
+--------------------------------------------------
+
+You need to enable these options in the menuconfig:
+
+    RTOS Features --->
+        Signal Configuration --->
+            [*] Default signal actions --->
+                [*] SIGINT and SIGKILL
+    Device Drivers --->
+        Serial Driver Support --->
+            [*] Serial TERMIOS support
+            [*]   Support SIGINT
+            (0x03)  Serial parse SIGINT characters
+
+Network
+=======
+
+How to detect Ethernet cable connection/disconnection?
+------------------------------------------------------
+
+NuttX supports Ethernet connection/disconnection events from Ethernet PHY
+using signals (see ``nuttx/drivers/net/phy_notify.c``).
+The network monitor thread at apps/netutils/netinit (see
+``CONFIG_NETINIT_MONITOR``) will handle taking the network down if the cable
+is unplugged and bringing it back up when the cable is restored.
+It is important to note that your Ethernet controller driver of your
+MCU needs to support CONFIG_ARCH_PHY_INTERRUPT (and implement
+``arch_phy_irq()``).
+

Documentation/index.rst

@@ -27,6 +27,7 @@ Last Updated: |today|
    components/index.rst
    applications/index.rst
    reference/index.rst
+   faq/index.rst
    guides/index.rst
    contributing/index.rst
    glossary.rst