Modify protocol to be more like DLPack.

Author: hameerabbasi

spec/draft/extensions/sparse_interchange.rst

@@ -10,7 +10,8 @@ Extension name and usage
 
 If implemented, this extension must be retrievable via::
 
-    >>> if hasattr(x, 'sparse'):
+    >>> xp = x.__array_namespace__()
+    >>> if hasattr(xp, 'sparse'):
     >>>     # Use the extension
 
 .. currentmodule:: array_api

src/array_api_stubs/_draft/array_object.py

@@ -1282,7 +1282,7 @@ def __binsparse__(
         Raises
         ------
         TypeError
-            If ``descriptor`` is not ``None``, and the array library does not support converting to it.
+            If ``descriptor`` is not ``None``, and the array library does not support converting to a format specified by it.
         """