Uppercase project name won't showcase the differences anymore

> Thanks to the capital P, Pello differs from the [normalized name](https://www.python.org/dev/peps/pep-0503/#normalized-name) pello, so we can show where each of them is needed.

[PEP 625](https://peps.python.org/pep-0625/#specification) specified the sdist filename to be equivalent to the name normalized according to the wheel specification.

This means following [these rules](https://packaging.python.org/en/latest/specifications/binary-distribution-format/#escaping-and-unicode):

```
In distribution names, any run of -_. characters (HYPHEN-MINUS, LOW LINE and FULL STOP) should be replaced with _ (LOW LINE), and uppercase characters should be replaced with corresponding lowercase ones.
```

As a result, once a new Pello version is released, there won't be any uppercase Pello in the resulting specfiles.

A better example would be a one with hyphens and undescores, as this is the only difference between the project name and sdist name normalization.

issue で参照されている project-name と sdist のメタデータを確認し、現在の結果をリンクされている PEP 503、PEP 625、および binary-distribution の命名規則と比較します。例でハイフンとアンダースコアを使用し、生成された sdist と specfiles に正規化の違いが目に見える形で示されれば完了です。

索引モデルが issue の本文から書いたものです。