Document how import chains are affected by `sys.setrecursionlimit`

While working on a very large Python codebase, I ran into some undocumented behaviour.

A chain of imports (i.e. one module imports another, which imports another, which imports another) will cause a RecursionError to be raised if the Python recursion limit is not high enough. (Note, there is no recursion involved.)

Longer chains of imports can be enabled by increasing the recursion limit. But the limit has no effect beyond a certain point (around 10,000). (I believe this is due to Py_C_RECURSION_LIMIT, mentioned in by Serhiy Storchaka.)

A workaround is available: you can import the modules in a different order.

I've created a repository with more analysis and scripts to reproduce the problem. I also started a Discuss topic on the subject.

From what I understand, this is a complex problem that is unlikely to be fixed. But I think it would be helpful to document this, probably in the docs for sys.setrecursionlimit.

I would be happy to try to do a pull request, assuming the core team agree that it should be added.

从 sys.setrecursionlimit 文档开始，并使用链接的 import-recursion-demo 仓库及其复现脚本来验证行为。完成标准是记录多长的导入链会触发 RecursionError、大致的上限，以及替代的导入顺序解决方法。