Typo in docs example code output

[npuichigo]

Currently there're many inconsistency code snippets in document, for example the example output is not consistent with example code https://pyo3.rs/v0.20.0/function/signature#using-pyo3signature--

[adamreichold]

Since you already checked that, maybe you could propose a pull request to resolve the issue? Thanks!

[npuichigo]

I'll collect the issues and fix in one PR