Add the description that 0 should not in the arg axes in keras.layers.dot() (#21718)

* Add the description that `0` should not in the arg `axes` in `keras.layers.dot()`

* Update keras/src/layers/merging/dot.py

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

* Update dot.py to fix the doc of `Dot` and `batch_dot`

---------

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: ILCSFNO

keras/src/layers/merging/dot.py

@@ -41,6 +41,7 @@ def batch_dot(x, y, axes=None):
         axes: Tuple or list of integers with target dimensions, or single
             integer. The sizes of `x.shape[axes[0]]` and `y.shape[axes[1]]`
             should be equal.
+            Note that axis `0` (the batch axis) cannot be included.
 
     Returns:
         A tensor with shape equal to the concatenation of `x`'s shape
@@ -226,7 +227,8 @@ class Dot(Merge):
             take the dot product. If a tuple, should be two integers
             corresponding to the desired axis from the first input and the
             desired axis from the second input, respectively. Note that the
-            size of the two selected axes must match.
+            size of the two selected axes must match, and that
+            axis `0` (the batch axis) cannot be included.
         normalize: Whether to L2-normalize samples along the dot product axis
             before taking the dot product. If set to `True`, then
             the output of the dot product is the cosine proximity
@@ -363,6 +365,7 @@ def dot(inputs, axes=-1, **kwargs):
         inputs: A list of input tensors (at least 2).
         axes: Integer or tuple of integers,
             axis or axes along which to take the dot product.
+            Note that axis `0` (the batch axis) cannot be included.
         normalize: Whether to L2-normalize samples along the
             dot product axis before taking the dot product.
             If set to `True`, then the output of the dot product