[API Compatibility No.2、35] fix doc -part (#77177)

* fix doc

* Update python/paddle/_paddle_docs.py

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: youge325

python/paddle/_paddle_docs.py

@@ -3361,8 +3361,9 @@ def allclose(
 add_doc_and_signature(
     "baddbmm",
     r"""
-    Performs a batch matrix-matrix product of matrices in input with matrices in batch1 and batch2,
-    and adds the result to input. The result is:
+    Perform batch matrix multiplication for input :math:`x` and :math:`y`.
+    :math:`input` is added to the final result.
+    The equation is:
     .. math::
         out = \beta \times input + \alpha \times x \times y
     where :math:`\beta` and :math:`\alpha` are scaling factors.