[3.14] gh-132983: Add documentation for compression.zstd (GH-133911)

Doc/library/archiving.rst

@@ -5,13 +5,15 @@ Data Compression and Archiving
 ******************************
 
 The modules described in this chapter support data compression with the zlib,
-gzip, bzip2 and lzma algorithms, and the creation of ZIP- and tar-format
+gzip, bzip2, lzma, and zstd algorithms, and the creation of ZIP- and tar-format
 archives.  See also :ref:`archiving-operations` provided by the :mod:`shutil`
 module.
 
 
 .. toctree::
 
+   compression.rst
+   compression.zstd.rst
    zlib.rst
    gzip.rst
    bz2.rst

Doc/library/compression.rst

@@ -0,0 +1,18 @@
+The :mod:`!compression` package
+===============================
+
+.. versionadded:: 3.14
+
+The :mod:`!compression` package contains the canonical compression modules
+containing interfaces to several different compression algorithms. Some of
+these modules have historically been available as separate modules; those will
+continue to be available under their original names for compatibility reasons,
+and will not be removed without a deprecation cycle. The use of modules in
+:mod:`!compression` is encouraged where practical.
+
+* :mod:`!compression.bz2` -- Re-exports :mod:`bz2`
+* :mod:`!compression.gzip` -- Re-exports :mod:`gzip`
+* :mod:`!compression.lzma` -- Re-exports :mod:`lzma`
+* :mod:`!compression.zlib` -- Re-exports :mod:`zlib`
+* :mod:`compression.zstd` -- Wrapper for the Zstandard compression library
+