cargo fmt now messes things up on windows

rustfmt.toml now has

`newline_style ="Unix"`

this really messes things up on windows since running cargo fmt now converts all line endings to unix.

git (and gitui) report this as a massive number of files being changed, which is hard to work thru.

Leaving it as Auto works fine on other projects and used to work for gitui when I first worked on it.

git (and gitui and github) convert the line endings correctly when copying down to windows (lf-> crlf) and when uploading back to github (crlf -> lf), this is done by leaving the gitconfig crlf setting as auto. (which is the default). So there is no need for this rustfmt setting, the line endings will be lf in github anyway regardless .

here is newly cloned repo running fmt check

```
PS C:\work\newgit2\gitui> cargo fmt -- --check
Incorrect newline style in \\?\C:\work\newgit2\gitui\asyncgit\src\asyncjob\mod.rs
Incorrect newline style in \\?\C:\work\newgit2\gitui\asyncgit\src\blame.rs
Incorrect newline style in \\?\C:\work\newgit2\gitui\asyncgit\src\branches.rs
Incorrect newline style in \\?\C:\work\newgit2\gitui\asyncgit\src\cached\branchname.rs
Incorrect newline style in \\?\C:\work\newgit2\gitui\asyncgit\src\cached\mod.rs
Incorrect newline style in \\?\C:\work\newgit2\gitui\asyncgit\src\commit_files.rs
...
```

it complains about every file because the clone down to windows converted all line endings to crlf

What I have to do at the moment is edit the rustfmt file to Auto.

Took me a while to work out why gitui / git suddenly starting saying all files had been changed

Apri rustfmt.toml e controlla l’impostazione newline_style. Esegui cargo fmt -- --check su un checkout Windows appena creato con terminatori di riga CRLF. Il lavoro è completato quando il checkout non segnala più ogni file Rust come formattato in modo errato, mentre i controlli di formattazione continuano a funzionare altrove.

Scritto dal modello di indicizzazione a partire dal testo della issue.