bpo-40833: Clarify Path.rename doc-string regarding relative paths (GH-20554)

diff --git a/Doc/library/pathlib.rst b/Doc/library/pathlib.rst
index 23486b6..9526a03 100644
--- a/Doc/library/pathlib.rst
+++ b/Doc/library/pathlib.rst
@@ -1008,6 +1008,10 @@
       >>> target.open().read()
       'some text'
 
+   The target path may be absolute or relative. Relative paths are interpreted
+   relative to the current working directory, *not* the directory of the Path
+   object.
+
    .. versionchanged:: 3.8
       Added return value, return the new Path instance.
 
@@ -1018,6 +1022,10 @@
    instance pointing to *target*.  If *target* points to an existing file or
    directory, it will be unconditionally replaced.
 
+   The target path may be absolute or relative. Relative paths are interpreted
+   relative to the current working directory, *not* the directory of the Path
+   object.
+
    .. versionchanged:: 3.8
       Added return value, return the new Path instance.