`index_generator.pagination_dir` doesn't take effect

[uiolee]

Check List

• [X] I have already read README.
• [X] I have already searched existing issues and they are not help to me.
• [X] I examined error or warning messages and it's difficult to solve.
• [X] I am using the latest version of this repository.
• [X] I am using the latest version of Hexo.
• [X] My Node.js is matched the required version.

Describe the bug

https://github.com/hexojs/hexo-generator-index/blob/f8ef61c1c8d2006d132d536657f0dee1b38d632a/README.md?plain=1#L21-L27

according to README, pagination_dir can be set by index_generator.pagination_dir. But from the code, index_generator.pagination_dir is invalid.

https://github.com/hexojs/hexo-generator-index/blob/f8ef61c1c8d2006d132d536657f0dee1b38d632a/lib/generator.js#L11

Expected behavior

Code and documentation should match, avoid misleading users.

How to reproduce

Screenshots

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Environment information

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Additional context

No response