Changing wording in fake_satpy_reading description

doc/source/dev_guide/testing.rst

@@ -3,4 +3,4 @@ Testing Satpy-based applications
 
 The ``satpy.testing`` modules provides tools for writing tests of applications that use Satpy.
 
-- For faking reading, you can use :func:`~satpy.testing.fake_satpy_reading`
+- To allow Scene creation and loading fake datasets without reading any data file: :func:`~satpy.testing.fake_satpy_reading`