Merge pull request #48 from dotnet-campus/t/lindexi/Copyright

更新版权信息

Author: ZhengDaoWang

Directory.Build.props

@@ -11,6 +11,6 @@
     <Description>A dotnet tool to assist in editing Office document files</Description>
 
     <RepositoryType>git</RepositoryType>
-    <Copyright>Copyright © 2020-2022 dotnet campus, All Rights Reserved.</Copyright> 
+    <Copyright>Copyright © 2020-$([System.DateTime]::Now.ToString(`yyyy`)) dotnet campus, All Rights Reserved.</Copyright> 
   </PropertyGroup>
 </Project>