fix: Added sourcelink ref

See
 https://mitchelsellers.com/blog/article/net-5-deterministic-builds-source-linking
 - for ensuring deterministic build flags and source link are set

Author: thargy

DevDecoder.DynamicXml/DevDecoder.DynamicXml.csproj

@@ -27,6 +27,14 @@
         <AssemblyName>DevDecoder.DynamicXml</AssemblyName>
         <PackageReadmeFile>README.md</PackageReadmeFile>
     </PropertyGroup>
+    
+    <PropertyGroup Condition="'$(GITHUB_ACTIONS)' == 'true'">
+        <ContinuousIntegrationBuild>true</ContinuousIntegrationBuild>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.0-beta-20204-02" PrivateAssets="All"/>
+    </ItemGroup>
 
     <ItemGroup>
         <None Update="DXStructs.tt">