tools: move scanpypi 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: Yegor Yefremov <yegorslists@googlemail.com>
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

@@ -15,6 +15,10 @@ scancpan
     a script to create a Buildroot package by scanning a CPAN module
     description.
 
+scanpypi
+    a script to create a Buildroot package by scanning a PyPI package
+    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