Improve section "Data Structures" in the tutorial

Documentation

The "More on Lists" subsection in the "Data Structures" section (Doc/tutorial/datastructures.rst) is the only place in the tutorial that contains formal definitions using Sphinx directives. They mostly duplicate descriptions in the library reference, and index entries refer to ones in the library reference, not in the tutorial. The list class is the only class whose methods are described so in the tutorial. The tutorial perhaps do not need such formal descriptions of all these methods. We could do like with other builtin functions and methods of other builtin classes, and simply add references to their real descriptions.

References to many methods of built classes did not work until recently. This might be one of reasons of exisiting such section.

This was discussed in https://discuss.python.org/t/a-small-typo-on-5-1-more-on-lists-section/106150. cc @nedbat

从 Doc/tutorial/datastructures.rst 及其 "More on Lists" 子节开始，然后将正式的方法描述与库参考文档中的对应描述进行比较。查看最近的讨论以了解上下文；完成的标准是教程避免不必要的重复定义，同时保留指向实际描述的有效引用。