Update the PackageProjectUrl links in the project files (fsprojects#458)

Author: Numpsy

src/Avalonia.FuncUI.Elmish/Avalonia.FuncUI.Elmish.fsproj

@@ -7,7 +7,7 @@
     <Product>Avalonia.FuncUI.Elmish</Product>
     <PackageId>Avalonia.FuncUI.Elmish</PackageId>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>
-    <PackageProjectUrl>https://github.com/FuncUI/Avalonia.FuncUI</PackageProjectUrl>
+    <PackageProjectUrl>https://github.com/fsprojects/Avalonia.FuncUI</PackageProjectUrl>
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
     <Title>Avalonia FuncUI Elmish</Title>
     <PackageVersion>$(FuncUIVersion)</PackageVersion>

src/Avalonia.FuncUI/Avalonia.FuncUI.fsproj

@@ -7,7 +7,7 @@
     <Product>Avalonia.FuncUI</Product>
     <PackageId>Avalonia.FuncUI</PackageId>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>
-    <PackageProjectUrl>https://github.com/FuncUI/Avalonia.FuncUI</PackageProjectUrl>
+    <PackageProjectUrl>https://github.com/fsprojects/Avalonia.FuncUI</PackageProjectUrl>
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
     <Title>Avalonia FuncUI</Title>
     <PackageVersion>$(FuncUIVersion)</PackageVersion>