Fix folder casing (#4144)

...et.Web.Client.ItemTemplates/content/Scss/styleSheet1.scss

...s/content/TypeScript/.template.config/dotnetcli.host.json

...mplates/content/TypeScript/.template.config/template.json

...tNet.Web.Client.ItemTemplates/content/TypeScript/file1.ts

...b.ItemTemplates/Microsoft.DotNet.Web.ItemTemplates.csproj

...es/content/RazorPage/.template.config/dotnetcli.host.json

...emplates/content/RazorPage/.template.config/template.json

...t.DotNet.Web.ItemTemplates/content/RazorPage/Index.cshtml

...otNet.Web.ItemTemplates/content/RazorPage/Index.cshtml.cs

.../content/ViewImports/.template.config/dotnetcli.host.json

...plates/content/ViewImports/.template.config/template.json

...Web.ItemTemplates/content/ViewImports/_ViewImports.cshtml

...es/content/ViewStart/.template.config/dotnetcli.host.json

...emplates/content/ViewStart/.template.config/template.json

...Net.Web.ItemTemplates/content/ViewStart/_ViewStart.cshtml

...ting/src/Microsoft.DotNet.Web.ProjectTemplates/.gitignore

...oft.DotNet.Web.ProjectTemplates/EmptyWeb-CSharp.csproj.in

...oft.DotNet.Web.ProjectTemplates/EmptyWeb-FSharp.fsproj.in

...ectTemplates/Microsoft.DotNet.Web.ProjectTemplates.csproj

...t.Web.ProjectTemplates/RazorClassLibrary-CSharp.csproj.in