GH-119054: Add "Reading directories" section to pathlib docs (#119956)

Add a dedicated subsection for `Path.iterdir()`-related methods,
specifically `iterdir()`, `glob()`, `rglob()` and `walk()`.

Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>

Doc/library/pathlib.rst

@@ -820,6 +820,9 @@ bugs or failures in your application)::
        % (cls.__name__,))
    UnsupportedOperation: cannot instantiate 'WindowsPath' on your system
 
+Some concrete path methods can raise an :exc:`OSError` if a system call fails
+(for example because the path doesn't exist).
+
 
 Parsing and generating URIs
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -1151,69 +1154,32 @@ Reading and writing files
    .. versionadded:: 3.5
 
 
-Other methods
-^^^^^^^^^^^^^
-
-Some of these methods can raise an :exc:`OSError` if a system call fails (for
-example because the path doesn't exist).
-
-
-.. classmethod:: Path.cwd()
-
-   Return a new path object representing the current directory (as returned
-   by :func:`os.getcwd`)::
-
-      >>> Path.cwd()
-      PosixPath('/home/antoine/pathlib')
-
-
-.. classmethod:: Path.home()
-
-   Return a new path object representing the user's home directory (as
-   returned by :func:`os.path.expanduser` with ``~`` construct). If the home
-   directory can't be resolved, :exc:`RuntimeError` is raised.
-
-   ::
-
-      >>> Path.home()
-      PosixPath('/home/antoine')
-
-   .. versionadded:: 3.5
-
-
-.. method:: Path.chmod(mode, *, follow_symlinks=True)
-
-   Change the file mode and permissions, like :func:`os.chmod`.
-
-   This method normally follows symlinks. Some Unix flavours support changing
-   permissions on the symlink itself; on these platforms you may add the
-   argument ``follow_symlinks=False``, or use :meth:`~Path.lchmod`.
-
-   ::
-
-      >>> p = Path('setup.py')
-      >>> p.stat().st_mode
-      33277
-      >>> p.chmod(0o444)
-      >>> p.stat().st_mode
-      33060
-
-   .. versionchanged:: 3.10
-      The *follow_symlinks* parameter was added.
+Reading directories
+^^^^^^^^^^^^^^^^^^^
 
-.. method:: Path.expanduser()
+.. method:: Path.iterdir()
 
-   Return a new path with expanded ``~`` and ``~user`` constructs,
-   as returned by :meth:`os.path.expanduser`. If a home directory can't be
-   resolved, :exc:`RuntimeError` is raised.
+   When the path points to a directory, yield path objects of the directory
+   contents::
 
-   ::
+      >>> p = Path('docs')
+      >>> for child in p.iterdir(): child
+      ...
+      PosixPath('docs/conf.py')
+      PosixPath('docs/_templates')
+      PosixPath('docs/make.bat')
+      PosixPath('docs/index.rst')
+      PosixPath('docs/_build')
+      PosixPath('docs/_static')
+      PosixPath('docs/Makefile')
 
-      >>> p = PosixPath('~/films/Monty Python')
-      >>> p.expanduser()
-      PosixPath('/home/eric/films/Monty Python')
+   The children are yielded in arbitrary order, and the special entries
+   ``'.'`` and ``'..'`` are not included.  If a file is removed from or added
+   to the directory after creating the iterator, it is unspecified whether
+   a path object for that file is included.
 
-   .. versionadded:: 3.5
+   If the path is not a directory or otherwise inaccessible, :exc:`OSError` is
+   raised.
 
 
 .. method:: Path.glob(pattern, *, case_sensitive=None, recurse_symlinks=False)
@@ -1281,43 +1247,6 @@ example because the path doesn't exist).
       The *pattern* parameter accepts a :term:`path-like object`.
 
 
-.. method:: Path.group(*, follow_symlinks=True)
-
-   Return the name of the group owning the file. :exc:`KeyError` is raised
-   if the file's gid isn't found in the system database.
-
-   This method normally follows symlinks; to get the group of the symlink, add
-   the argument ``follow_symlinks=False``.
-
-   .. versionchanged:: 3.13
-      Raises :exc:`UnsupportedOperation` if the :mod:`grp` module is not
-      available. In previous versions, :exc:`NotImplementedError` was raised.
-
-   .. versionchanged:: 3.13
-      The *follow_symlinks* parameter was added.
-
-
-.. method:: Path.iterdir()
-
-   When the path points to a directory, yield path objects of the directory
-   contents::
-
-      >>> p = Path('docs')
-      >>> for child in p.iterdir(): child
-      ...
-      PosixPath('docs/conf.py')
-      PosixPath('docs/_templates')
-      PosixPath('docs/make.bat')
-      PosixPath('docs/index.rst')
-      PosixPath('docs/_build')
-      PosixPath('docs/_static')
-      PosixPath('docs/Makefile')
-
-   The children are yielded in arbitrary order, and the special entries
-   ``'.'`` and ``'..'`` are not included.  If a file is removed from or added
-   to the directory after creating the iterator, whether a path object for
-   that file be included is unspecified.
-
 .. method:: Path.walk(top_down=True, on_error=None, follow_symlinks=False)
 
    Generate the file names in a directory tree by walking the tree
@@ -1413,6 +1342,84 @@ example because the path doesn't exist).
 
    .. versionadded:: 3.12
 
+
+Other methods
+^^^^^^^^^^^^^
+
+.. classmethod:: Path.cwd()
+
+   Return a new path object representing the current directory (as returned
+   by :func:`os.getcwd`)::
+
+      >>> Path.cwd()
+      PosixPath('/home/antoine/pathlib')
+
+
+.. classmethod:: Path.home()
+
+   Return a new path object representing the user's home directory (as
+   returned by :func:`os.path.expanduser` with ``~`` construct). If the home
+   directory can't be resolved, :exc:`RuntimeError` is raised.
+
+   ::
+
+      >>> Path.home()
+      PosixPath('/home/antoine')
+
+   .. versionadded:: 3.5
+
+
+.. method:: Path.chmod(mode, *, follow_symlinks=True)
+
+   Change the file mode and permissions, like :func:`os.chmod`.
+
+   This method normally follows symlinks. Some Unix flavours support changing
+   permissions on the symlink itself; on these platforms you may add the
+   argument ``follow_symlinks=False``, or use :meth:`~Path.lchmod`.
+
+   ::
+
+      >>> p = Path('setup.py')
+      >>> p.stat().st_mode
+      33277
+      >>> p.chmod(0o444)
+      >>> p.stat().st_mode
+      33060
+
+   .. versionchanged:: 3.10
+      The *follow_symlinks* parameter was added.
+
+.. method:: Path.expanduser()
+
+   Return a new path with expanded ``~`` and ``~user`` constructs,
+   as returned by :meth:`os.path.expanduser`. If a home directory can't be
+   resolved, :exc:`RuntimeError` is raised.
+
+   ::
+
+      >>> p = PosixPath('~/films/Monty Python')
+      >>> p.expanduser()
+      PosixPath('/home/eric/films/Monty Python')
+
+   .. versionadded:: 3.5
+
+
+.. method:: Path.group(*, follow_symlinks=True)
+
+   Return the name of the group owning the file. :exc:`KeyError` is raised
+   if the file's gid isn't found in the system database.
+
+   This method normally follows symlinks; to get the group of the symlink, add
+   the argument ``follow_symlinks=False``.
+
+   .. versionchanged:: 3.13
+      Raises :exc:`UnsupportedOperation` if the :mod:`grp` module is not
+      available. In previous versions, :exc:`NotImplementedError` was raised.
+
+   .. versionchanged:: 3.13
+      The *follow_symlinks* parameter was added.
+
+
 .. method:: Path.lchmod(mode)
 
    Like :meth:`Path.chmod` but, if the path points to a symbolic link, the