Add logging example to documentation

Judging by the issues on this package and graphene, a lot of users struggle with graphql-core's decision to catch all exceptions. I see that in #41 something was done to make this easier, but it's not clear how to use it. An example of logging/error handling in the documentation would go a long way.

首先阅读 #41 中引用的 issue，以了解现有的异常处理变更，然后检查当前文档以确定合适的位置。添加一个文档示例，展示如何记录和处理 graphql-core 捕获的异常，并确认其中说明了如何在实践中使用此行为。

由索引模型根据 Issue 内容生成。