scripts: add README

closes #10291

Author: SomberNight

electrum/scripts/README.md

@@ -0,0 +1,6 @@
+These are scripts and small utilities developers or power-users might find interesting.
+
+They are standalone, don't depend on each other and nothing depends on them.
+Neither the GUI nor the CLI should depend on these in any way.
+
+The scripts use electrum as a python library, sometimes as a goal in itself, to showcase how to script something.