updated the dotnet command

[pictos]

The -i is obsolete and produce warnings.

GitHub Issue (If applicable): #

PR Type

What kind of change does this PR introduce?

• Documentation content changes

What is the current behavior?

When install the uno-extension template using the
dotnet new -i Uno.Extensions.Templates the tooling prints a warning message.

What is the new behavior?

No warning message and everyone was happy (:

PR Checklist

Please check if your PR fulfills the following requirements:

• Tested code with current supported SDKs
• Docs have been added/updated which fit documentation template. (for bug fixes / features)
• Unit Tests and/or UI Tests for the changes have been added (for bug fixes / features) (if applicable)
• Wasm UI Tests are not showing unexpected any differences. Validate PR Screenshots Compare Test Run results.
• Contains NO breaking changes
• Updated the Release Notes
• Associated with an issue (GitHub or internal)

Other information

Internal Issue (If applicable):

[welcome]

Congrats on your first pull-request! We ❤ the people who are involved in this project, and we’d love to pay it forward by sending you some swag. If you have any feedback (or ideas how to improve Uno as a open-source project) please open a feedback issue.

Merci beaucoup 👋