Add link to the detailed

fd-inheritance documentation as suggested by vstinner.

Author: raixyzaditya

Doc/library/tempfile.rst

@@ -228,8 +228,11 @@ The module defines the following user-callable items:
    the file is executable by no one.
 
    The file descriptor is not inherited by child processes across
-   :func:`exec <os.execl>` calls.
-
+   :func:`exec <os.execl>` calls, but will be inherited by child
+   processes created via :func:`os.fork`. See 
+   `File Descriptor Inheritance <https://docs.python.org/dev/library/os.html#fd-inheritance>`_
+   for more information.
+   
    Unlike :func:`TemporaryFile`, the user of :func:`mkstemp` is responsible
    for deleting the temporary file when done with it.