Docs: inline markup in `c-api/typeobj.rst` legend is not rendered because of `.. code-block:: none`

Documentation

In Doc/c-api/typeobj.rst, the two legends that explain the "D" (default) and "I" (inheritance) columns of the PyTypeObject quick-reference table (lines 172–187) are wrapped in .. code-block:: none. Because code-block renders its content verbatim:

• *PyType_Ready* and *NULL* appear with literal asterisks.
• PyType_Ready is plain text instead of a cross-reference to :c:func:PyType_Ready.
• NULL is plain text instead of the NULL inline literal used elsewhere in the same file.

Linked PRs

• gh-148962

打开 Doc/c-api/typeobj.rst，检查第 172–187 行附近的两个 legend。检查文件其他位置的已渲染文档如何处理 PyType_Ready 交叉引用和 NULL 内联字面量。完成的标准是两个 legend 都渲染 markup，而不是字面量星号，并采用预期的引用和字面量格式。