remove chunk encoding configuration from docs

Author: d-v-b

docs/user-guide/arrays.rst

@@ -246,16 +246,6 @@ built-in delta filter::
    >>> z.compressors
    (LZMA(codec_name='numcodecs.lzma', codec_config={'filters': [{'id': 3, 'dist': 4}, {'id': 33, 'preset': 1}]}),)
 
-The default compressor can be changed by setting the value of the using Zarr's
-:ref:`user-guide-config`, e.g.::
-
-   >>> with zarr.config.set({'array.v2_default_compressor.default': {'id': 'blosc'}}):
-   ...     z = zarr.create_array(store={}, shape=(100000000,), chunks=(1000000,), dtype='int32', zarr_format=2)
-   >>> z.filters
-   ()
-   >>> z.compressors
-   (Blosc(cname='lz4', clevel=5, shuffle=SHUFFLE, blocksize=0),)
-
 To disable compression, set ``compressors=None`` when creating an array, e.g.::
 
    >>> z = zarr.create_array(store='data/example-8.zarr', shape=(100000000,), chunks=(1000000,), dtype='int32', compressors=None)

docs/user-guide/config.rst

@@ -43,25 +43,7 @@ This is the current default configuration::
 
    >>> zarr.config.pprint()
    {'array': {'order': 'C',
-            'v2_default_compressor': {'default': {'checksum': False,
-                                                   'id': 'zstd',
-                                                   'level': 0},
-                                       'variable-length-string': {'checksum': False,
-                                                                  'id': 'zstd',
-                                                                  'level': 0}},
-            'v2_default_filters': {'default': None,
-                                    'variable-length-string': [{'id': 'vlen-utf8'}]},
-            'v3_default_compressors': {'default': [{'configuration': {'checksum': False,
-                                                                        'level': 0},
-                                                      'name': 'zstd'}],
-                                       'variable-length-string': [{'configuration': {'checksum': False,
-                                                                                       'level': 0},
-                                                                     'name': 'zstd'}]},
-            'v3_default_filters': {'default': [], 'variable-length-string': []},
-            'v3_default_serializer': {'default': {'configuration': {'endian': 'little'},
-                                                   'name': 'bytes'},
-                                       'variable-length-string': {'name': 'vlen-utf8'}},
-            'write_empty_chunks': False},
+              'write_empty_chunks': False},
    'async': {'concurrency': 10, 'timeout': None},
    'buffer': 'zarr.buffer.cpu.Buffer',
    'codec_pipeline': {'batch_size': 1,