v2.1.0 release notes (#777)

* v2.1.0 release notes

* Highlight breaking change

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: TomNicholas

docs/releases.md

@@ -1,6 +1,11 @@
 # Release notes
 
-## v2.0.2 (unreleased)
+## v2.1.0 (14th August 2025)
+
+This release fixes a number of important bugs that could silently lead to referenced data being read back incorrectly.
+In particular, note that writing virtual chunks to Icechunk now requires that all virtual chunk containers are set correctly by default.
+It also unpins our dependency on xarray, so that VirtualiZarr is compatible with the latest released version of Xarray.
+Please upgrade!
 
 ### New Features
 
@@ -28,6 +33,9 @@
 
 ### Documentation
 
+- Updated Icechunk examples now that virtual chunk containers are required by default ([#774](https://github.com/zarr-developers/VirtualiZarr/pull/774)).
+  By [Tom Nicholas](https://github.com/TomNicholas).
+
 ### Internal changes
 
 - `extract_codecs` function inside `convert_to_codec_pipeline` now raises if it encounters a codec which does not inherit from the correct `zarr.abc.codec` base classes. ([#775](https://github.com/zarr-developers/VirtualiZarr/pull/775)).