gh-144329: Clarify that ._pth files are Windows-only in site docs

Author: Muawiya-contact

Doc/library/site.rst

@@ -78,19 +78,18 @@ directory rather than a file.  No item is added to ``sys.path`` more than
 once.  Blank lines and lines beginning with ``#`` are skipped.  Lines starting
 with ``import`` (followed by space or tab) are executed.
 
+.. note::
+   On Windows, a file whose name has the form :file:`._pth` is handled 
+   differently; it is used by the Windows-only "embeddable distribution" 
+   to provide a self-contained Python environment. See 
+   :ref:`finding_modules` for more details.
+
 .. note::
 
    An executable line in a :file:`.pth` file is run at every Python startup,
    regardless of whether a particular module is actually going to be used.
    Its impact should thus be kept to a minimum.
-   The primary intended purpose of executable lines is to make the
-   corresponding module(s) importable
-   (load 3rd-party import hooks, adjust :envvar:`PATH` etc).
-   Any other initialization is supposed to be done upon a module's
-   actual import, if and when it happens.
-   Limiting a code chunk to a single line is a deliberate measure
-   to discourage putting anything more complex here.
-
+   
 .. versionchanged:: 3.13
    The :file:`.pth` files are now decoded by UTF-8 at first and then by the
    :term:`locale encoding` if it fails.