Update README.rst about patched for numba-dppy

We have to mention that IntelPython/numba differs from original Numba.

Author: PokhodenkoSA

README.rst

@@ -1,5 +1,5 @@
 *****
-Numba
+Numba with patches for numba-dppy
 *****
 
 .. image:: https://badges.gitter.im/numba/numba.svg
@@ -10,6 +10,14 @@ Numba
    :target: https://numba.discourse.group/
    :alt: Discourse
 
+Patches for numba-dppy
+######################
+
+See https://github.com/IntelPython/numba-dppy.
+If `numba-dppy` package is installed this version of Numba provides
+additional features.
+Without `numba-dppy` package this version of Numba works like original Numba.
+
 A Just-In-Time Compiler for Numerical Functions in Python
 #########################################################