bpo-40204: Fix duplicates in the documentation (GH-21857)
Fix two Sphinx 3 issues:
Doc/c-api/buffer.rst:304: WARNING: Duplicate C declaration, also defined in 'c-api/buffer'.
Declaration is 'PyBUF_ND'.
Doc/c-api/unicode.rst:1603: WARNING: Duplicate C declaration, also defined in 'c-api/unicode'.
Declaration is 'PyObject* PyUnicode_Translate(PyObject *str, PyObject *table, const char *errors)'.
diff --git a/Doc/c-api/buffer.rst b/Doc/c-api/buffer.rst
index fc1430e..ddb28af 100644
--- a/Doc/c-api/buffer.rst
+++ b/Doc/c-api/buffer.rst
@@ -301,7 +301,7 @@
+-----------------------------------+-------+---------+------------+--------+
| .. c:macro:: PyBUF_ANY_CONTIGUOUS | yes | yes | NULL | C or F |
+-----------------------------------+-------+---------+------------+--------+
-| .. c:macro:: PyBUF_ND | yes | NULL | NULL | C |
+| :c:macro:`PyBUF_ND` | yes | NULL | NULL | C |
+-----------------------------------+-------+---------+------------+--------+