Fix typo in SDK reference

Author: kzu

src/Demo/nuget.config

@@ -2,7 +2,7 @@
 <configuration>
   <packageSources>
     <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
-    <add key="kzu" value="https://api.kzu.app/index.json" />
+    <add key="kzu" value="https://pkg.kzu.app/index.json" />
     <add key="local" value="../../bin/" />
   </packageSources>
   <activePackageSource>

src/SmallSharp/Sdk.props

@@ -14,7 +14,7 @@
   <!-- Import Common.props explicitly we're too early here to use MSBuildProjectExtensionsPath -->
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="'$(MicrosoftCommonPropsHasBeenImported)' != 'true' and Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
 
-  <Import Project="Sdk.props" Sdk="Microsoft.NET.SDK"
+  <Import Project="Sdk.props" Sdk="Microsoft.NET.Sdk"
        Condition="!Exists('$(MSBuildProjectExtensionsPath)SmallSharp.sdks.props')" />
 
   <Import Project="$(MSBuildProjectExtensionsPath)SmallSharp.sdks.props" 

src/SmallSharp/Sdk.targets

@@ -1,6 +1,6 @@
 <Project>
 
-  <Import Project="Sdk.targets" Sdk="Microsoft.NET.SDK"
+  <Import Project="Sdk.targets" Sdk="Microsoft.NET.Sdk"
        Condition="!Exists('$(MSBuildProjectExtensionsPath)SmallSharp.sdks.targets')" />
 
   <Import Project="$(MSBuildProjectExtensionsPath)SmallSharp.sdks.targets"