Reword tutorials index text

Author: melissawm

doc/source/user/tutorials_index.rst

@@ -4,9 +4,6 @@
 NumPy Tutorials
 ################
 
-These documents are intended as an introductory overview of NumPy and its 
-features, as well as a few applications. You can find them 
-`in the NumPy Tutorials page <https://numpy.org/numpy-tutorials>`_.
-
-For detailed reference documentation of the functions and
-classes contained in the package, see the :ref:`API reference <reference>`.
+Tutorials about NumPy are hosted at https://numpy.org/numpy-tutorials. For
+how-tos, reference documents, and explanations see the 
+:ref:`API reference <reference>` documentation.