tools: move scancpan out of support/scripts/

Move it to the top-level tools/ directory, so that it is easier to
find for users.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: "François Perrad" <francois.perrad@gadz.org>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Arnout Vandecappelle <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

tools/readme.txt

@@ -11,6 +11,10 @@ get-developpers
     of Buildroot, so they can be Cc:ed on a mail. Accepts a patch as
     input, a package name or and architecture name.
 
+scancpan
+    a script to create a Buildroot package by scanning a CPAN module
+    description.
+
 size-stat-compare
     a script to compare the rootfs size between two differnt Buildroot
     configurations. This can be used to identify the size impact of