Create package source mapping

Author: hez2010

nuget.config

@@ -1,9 +1,20 @@
 <?xml version="1.0" encoding="utf-8"?>
 <configuration>
-    <packageSources>
-        <clear />
-        <add key="NuGet Gallery" value="https://api.nuget.org/v3/index.json" />
-        <add key="Project Packages" value="src/Files.App/Assets/Libraries/" />
-        <add key="Toolkit Labs" value="https://pkgs.dev.azure.com/dotnet/CommunityToolkit/_packaging/CommunityToolkit-Labs/nuget/v3/index.json" />
-    </packageSources>
+  <packageSources>
+    <clear />
+    <add key="NuGet Gallery" value="https://api.nuget.org/v3/index.json" />
+    <add key="Project Packages" value="src/Files.App/Assets/Libraries/" />
+    <add key="Toolkit Labs" value="https://pkgs.dev.azure.com/dotnet/CommunityToolkit/_packaging/CommunityToolkit-Labs/nuget/v3/index.json" />
+  </packageSources>
+  <packageSourceMapping>
+    <packageSource key="Project Packages">
+      <package pattern="SevenZipSharp" />
+    </packageSource>
+    <packageSource key="Toolkit Labs">
+      <package pattern="CommunityToolkit.Labs.*" />
+    </packageSource>
+    <packageSource key="NuGet Gallery">
+      <package pattern="*" />
+    </packageSource>
+  </packageSourceMapping>
 </configuration>