[media] doc-rst: convert udev chapter to rst

This chapter is outdated. I almost removed, but, as we're lacking
documentation about how to make DVB devices persistent, I opted,
instead, to keep it, and add a note about that.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/media/dvb-drivers/index.rst

@@ -29,4 +29,5 @@ License".
 	opera-firmware
 	technisat
 	ttusb-dec
+	udev
 	contributors

Documentation/media/dvb-drivers/udev.rst

@@ -1,9 +1,22 @@
+UDEV rules for DVB
+==================
+
+.. note::
+
+   #) This documentation is outdated. Udev on modern distributions auto-detect
+      the DVB devices.
+
+   #) **TODO:** change this document to explain how to make DVB devices
+      persistent, as, when a machine has multiple devices, they may be detected
+      on different orders, which could cause apps that relies on the device
+      numbers to fail.
+
 The DVB subsystem currently registers to the sysfs subsystem using the
 "class_simple" interface.
 
 This means that only the basic information like module loading parameters
 are presented through sysfs. Other things that might be interesting are
-currently *not* available.
+currently **not** available.
 
 Nevertheless it's now possible to add proper udev rules so that the
 DVB device nodes are created automatically.
@@ -21,10 +34,11 @@ The script should be called "dvb.sh" and should be placed into a script
 dir where udev can execute it, most likely /etc/udev/scripts/
 
 So, create a new file /etc/udev/scripts/dvb.sh and add the following:
-------------------------------schnipp------------------------------------------------
-#!/bin/sh
-/bin/echo $1 | /bin/sed -e 's,dvb\([0-9]\)\.\([^0-9]*\)\([0-9]\),dvb/adapter\1/\2\3,'
-------------------------------schnipp------------------------------------------------
+
+.. code-block:: none
+
+	#!/bin/sh
+	/bin/echo $1 | /bin/sed -e 's,dvb\([0-9]\)\.\([^0-9]*\)\([0-9]\),dvb/adapter\1/\2\3,'
 
 Don't forget to make the script executable with "chmod".
 
@@ -34,9 +48,10 @@ directory for rule files. The main udev configuration file /etc/udev/udev.conf
 will tell you the directory where the rules are, most likely it's /etc/udev/rules.d/
 
 Create a new rule file in that directory called "dvb.rule" and add the following line:
-------------------------------schnipp------------------------------------------------
-KERNEL="dvb*", PROGRAM="/etc/udev/scripts/dvb.sh %k", NAME="%c"
-------------------------------schnipp------------------------------------------------
+
+.. code-block:: none
+
+	KERNEL="dvb*", PROGRAM="/etc/udev/scripts/dvb.sh %k", NAME="%c"
 
 If you want more control over the device nodes (for example a special group membership)
 have a look at "man udev".