Document concurrency

I'm curious what model is used to bridge Python and golang concurrency models.
I wish it was documented :)

Python has threads (1:1 mapped to lightweight system processes) and asyncio, explicit and quite so different.

Go has special handling for cpu-bound and io-bound goroutines, transparent to the user.

How would someone use `gopy` to interface go's amazing `net/http` module or some go package that wraps it? As in, how should Python code look like to benefit from go's concurrency?

该 issue 提到了 gopy 和 Go's net/http，但没有指定文件或测试。首先检查 gopy 的现有文档和生成的 CPython 扩展的行为，然后确定 Python 调用方将如何使用带有并发的 Go package。文档解释 Python/Go 并发桥接并展示如何使用类似 net/http 的 package，即视为完成。

由索引模型根据 Issue 内容生成。