[OTHER] .NET icon folder is inconsistent with naming convention

### I have searched through the issues and didn't find my problem.

- [X] Confirm

### What would you like to share?

The [naming convention](https://github.com/devicons/devicon/wiki/Naming-Conventions) for icon folders (and icons) is to join all the words in the name, without any delimiters. The .NET (dot-net) folder though, is inconsistent with this convention.

This can be fixed by renaming the folder and icons to be `dotnet` in one word. To ensure that `dot-net` still shows up in searches, it can be added to the list of altnames.
https://github.com/devicons/devicon/tree/develop/icons/dot-net
#### Folder
#### Icons

### Additional information

_No response_

Inizia nella cartella icons/dot-net e confronta i nomi della cartella e delle icone con il wiki naming-conventions. Rinomina la cartella e le icone in dotnet, quindi verifica che dot-net rimanga disponibile tramite l’elenco altname del progetto e che le risorse delle icone aggiornate vengano trovate correttamente.

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