[pallas] Added a CHANGELOG for Pallas

The CHANGELOG is populated with the changes since June 10th, when
JAX 0.4.29 was released.

CHANGELOG.md

@@ -1,6 +1,8 @@
 # Change log
 
 Best viewed [here](https://jax.readthedocs.io/en/latest/changelog.html).
+For the changes specific to the experimental Pallas APIs,
+see {ref}`pallas-changelog`.
 
 <!--
 Remember to align the itemized text with the first line of an item within a list.

docs/pallas/CHANGELOG.md

@@ -0,0 +1,48 @@
+(pallas-changelog)=
+
+# Pallas Changelog
+
+<!--* freshness: { reviewed: '2024-07-11' } *-->
+
+This is the list of changes specific to {class}`jax.experimental.pallas`.
+For the overall JAX change log see [here](https://jax.readthedocs.io/en/latest/changelog.html).
+
+<!--
+Remember to align the itemized text with the first line of an item within a list.
+-->
+
+## Released with JAX 0.4.31
+
+* Changes
+  * {class}`jax.experimental.pallas.BlockSpec` now expects `block_shape` to
+    be passed *before* `index_map`. The old argument order is deprecated and
+    will be removed in a future release.
+  * Fixed the interpreter mode to work with BlockSpec that involve padding
+    ({jax-issue}`#22275`).
+    Padding in interpreter mode will be with NaN, to help debug out-of-bounds
+    errors, but this behavior is not present when running in custom kernel mode,
+    and should not be depended on.
+
+
+* Deprecations
+
+
+* New Functionality
+  * Added documentation for BlockSpec: {ref}`pallas_grids_and_blockspecs`.
+  * Improved error messages for the {func}`jax.experimental.pallas.pallas_call`
+    API.
+  * Added lowering rules for TPU for `lax.shift_right_arithmetic` ({jax-issue}`#22279`)
+    and `lax.erf_inv` ({jax-issue}`#22310`).
+  * Added initial support for shape polymorphism for the Pallas TPU custom kernels\
+    ({jax-issue}`#22084`).
+
+## Released with JAX 0.4.30 (June 18, 2024)
+
+* New Functionality
+  * Added checkify support for {func}`jax.experimental.pallas.pallas_call` in
+    interpret mode ({jax-issue}`#21862`).
+  * Improved support for PRNG keys for TPU kernels ({jax-issue}`#21773`).
+
+
+
+

docs/pallas/index.rst

@@ -6,6 +6,10 @@ Pallas is an extension to JAX that enables writing custom kernels for GPU and TP
 This section contains tutorials, guides and examples for using Pallas.
 See also the :class:`jax.experimental.pallas` module API documentation.
 
+.. warning::
+  Pallas is experimental and is changing frequently.
+  See the :ref:`pallas-changelog` for the recent changes.
+
 .. toctree::
    :caption: Guides
    :maxdepth: 2
@@ -14,9 +18,14 @@ See also the :class:`jax.experimental.pallas` module API documentation.
    design
    grid_blockspec
 
+
 .. toctree::
    :caption: Platform Features
    :maxdepth: 2
 
    tpu/index
 
+.. toctree::
+   :maxdepth: 1
+
+   CHANGELOG