Remove “generally equivalent” phrasing as per review feedback

Removed redundant explanation of array size calculation.

Author: Yashp002

Doc/c-api/intro.rst

@@ -313,12 +313,7 @@ complete listing.
    compilation error, otherwise, using this macro with a pointer will
    produce incorrect results.
 
-   This is generally equivalent to::
-
-      sizeof(array) / sizeof((array)[0])
-
-
-
+   
 .. _api-objects:
 
 Objects, Types and Reference Counts