enable nuget audit (#1491)

* enable nuget audit

src/Directory.build.props

@@ -15,5 +15,7 @@
   </ItemGroup>
   <PropertyGroup Condition="'$(TF_BUILD)' == 'true'">
     <ContinuousIntegrationBuild>true</ContinuousIntegrationBuild>
+    <NuGetAuditMode>all</NuGetAuditMode>
+    <NuGetAuditLevel>low</NuGetAuditLevel>
   </PropertyGroup>
 </Project>

src/Humanizer.Tests/Humanizer.Tests.csproj

@@ -12,7 +12,7 @@
     <PackageReference Include="Verify.DiffPlex" Version="2.3.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
     <ProjectReference Include="..\Humanizer\Humanizer.csproj" />
-    <Reference Include="System.ComponentModel.DataAnnotations" Condition="'$(TargetFramework)' == 'net48' "/>
+    <Reference Include="System.ComponentModel.DataAnnotations" Condition="'$(TargetFramework)' == 'net48' " />
     <Content Include="xunit.runner.json">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>

src/nuget.config

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+  <config>
+    <add key="signatureValidationMode" value="require" />
+  </config>
+  <packageSources>
+    <clear />
+    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" protocolVersion="3" />
+  </packageSources>
+  <trustedSigners>
+    <repository name="nuget.org" serviceIndex="https://api.nuget.org/v3/index.json">
+      <!-- Current: expires May 15, 2024 -->
+      <certificate fingerprint="5A2901D6ADA3D18260B9C6DFE2133C95D74B9EEF6AE0E5DC334C8454D1477DF4"
+                   hashAlgorithm="SHA256"
+                   allowUntrustedRoot="false" />
+      <!-- Next -->
+      <certificate fingerprint="1F4B311D9ACC115C8DC8018B5A49E00FCE6DA8E2855F9F014CA6F34570BC482D"
+                   hashAlgorithm="SHA256"
+                   allowUntrustedRoot="false" />
+    </repository>
+  </trustedSigners>
+</configuration>