Documentation: fix reference to deprecated url

http://www.lm-sensors.org/wiki/UsefulLinks no longer exists.
Replace the link with working references.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>

doc/progs

@@ -6,8 +6,11 @@ These programs are generally small utilities used for debugging,
 and installation of the lm_sensors package, and for demonstrating
 the use of the drivers and libraries in this package.
 For more elaborate programs (for example, GUI sensor displays),
-see http://www.lm-sensors.org/wiki/UsefulLinks.
-
+see https://github.com/groeck/lm-sensors/
+    http://sensors-applet.sourceforge.net/
+    https://01.org/powertop/
+    https://wpitchoune.net/psensor/
+    https://amanusk.github.io/s-tui/
 
 * prog/daemon/healthd.sh (written in bash, not installed)
   An example of a very simple hardware health monitoring daemon.