Delete warning in approximation documentation (#6221)

* Add warning in community doc

* Delete warning in approximation

* undo unwanted changes

* Minor formatting nits.

---------

Co-authored-by: Ross Barnowski <rossbar@berkeley.edu>

networkx/algorithms/approximation/__init__.py

@@ -1,12 +1,12 @@
 """Approximations of graph properties and Heuristic methods for optimization.
 
-    .. warning:: These functions are not imported in the top-level of ``networkx``
+The functions in this class are not imported into the top-level ``networkx``
+namespace so the easiest way to use them is with::
 
-    These functions can be accessed using
-    ``networkx.approximation.function_name``
+    >>> from networkx.algorithms import approximation
 
-    They can be imported using ``from networkx.algorithms import approximation``
-    or ``from networkx.algorithms.approximation import function_name``
+Another option is to import the specific function with
+``from networkx.algorithms.approximation import function_name``.
 
 """
 from networkx.algorithms.approximation.clustering_coefficient import *