Add application stylesheet link to _Layout.cshtml

[ChrisDoernen]

I experienced the problem that CSS isolation was not working after I created an app using MudBlazor templates, by running dotnet new mudblazor --host server--name MyApplication as described in the getting started guide.

As I have not much experience with Blazor, it took a too much time finding out that the line <link href="MyApplication.styles.css" rel="stylesheet" /> is "missing", compared to what the dotnet new blazorserver command does.

I guess to add the stylesheet link statement in the head section in the _Layout.cshtml for Blazor Server apps should be fairly easy. If I find some time, I'd be happy to see if I can provide a PR.

MudBlazor is just awesome!

[ChrisDoernen]

I see that the application name in the stylesheet filename would have to be replaced with the user input from the command somehow... I can not find another place where that is done so far.

[ChrisDoernen]

Sorry guys, this duplicates #42

Should have scanned through the issues first.