Update documentation of remote store (#3212)

* Add doc about custom remote storage

* Add doc about store type to `FsspecStore.from_url`

* Add changes

* Fix example code

* Run pre-commit

* Fix typo

---------

Co-authored-by: Davis Bennett <davis.v.bennett@gmail.com>

Author: bevilacqc

changes/3212.doc.rst

@@ -0,0 +1,4 @@
+- Add a description on how to create a RemoteStore of a specific filesystem to the `Remote Store` section in `docs\user-guide\storage.rst`.
+- State in the docstring of `FsspecStore.from_url` that the filesystem type is inferred from the URL scheme.
+
+It should help a user handling the case when the type of FsspecStore doesn't match the URL scheme.

docs/user-guide/storage.rst

@@ -87,6 +87,16 @@ API. ``storage_options`` can be used to configure the fsspec backend.:
    >>> zarr.open_group(store=store, mode='r')
    <Group <FsspecStore(S3FileSystem, noaa-nwm-retro-v2-zarr-pds)>>
 
+The type of filesystem (e.g. S3, https, etc..) is inferred from the scheme of the url (e.g. s3 for "**s3**://noaa-nwm-retro-v2-zarr-pds").
+In case a specific filesystem is needed, one can explicitly create it. For example to create a S3 filesystem:
+
+   >>> import fsspec
+   >>> fs = fsspec.filesystem(
+   ...    's3', anon=True, asynchronous=True,
+   ...    client_kwargs={'endpoint_url': "https://noaa-nwm-retro-v2-zarr-pds.s3.amazonaws.com"}
+   ... )
+   >>> store = zarr.storage.FsspecStore(fs)
+
 Memory Store
 ~~~~~~~~~~~~
 

src/zarr/storage/_fsspec.py

@@ -216,7 +216,7 @@ def from_url(
         allowed_exceptions: tuple[type[Exception], ...] = ALLOWED_EXCEPTIONS,
     ) -> FsspecStore:
         """
-        Create a FsspecStore from a URL.
+        Create a FsspecStore from a URL. The type of store is determined from the URL scheme.
 
         Parameters
         ----------