Merge pull request numpy#15125 from bashtage/remove-basic-rng

DOC: Remove reference to basic RNG

Author: mattip

doc/source/reference/random/extending.rst

@@ -41,8 +41,8 @@ wrap around, providing array alignment information -- still apply.
     :language: cython
     :end-before: example 2
 
-The BitGenerator can also be directly accessed using the members of the basic
-RNG structure.
+The BitGenerator can also be directly accessed using the members of the ``bitgen_t``
+struct.
 
 .. literalinclude:: ../../../../numpy/random/_examples/cython/extending_distributions.pyx
     :language: cython
@@ -70,9 +70,9 @@ directly from the ``_generator`` shared object, using the `BitGenerator.cffi` in
     :start-after: dlopen
 
 
-New Basic RNGs
-==============
-`~Generator` can be used with other user-provided BitGenerators. The simplest
+New Bit Generators
+==================
+`~Generator` can be used with user-provided `~BitGenerator`\ s. The simplest
 way to write a new BitGenerator is to examine the pyx file of one of the
 existing BitGenerators. The key structure that must be provided is the
 ``capsule`` which contains a ``PyCapsule`` to a struct pointer of type