Update nuget.yml

Author: CRThu

.github/workflows/nuget.yml

@@ -40,7 +40,7 @@ jobs:
         --configuration Release `
         --no-build `
         --output ${{ github.workspace }}/nuget-packages `
-        -p:PackageReadmeFile=README.md `
+        -p:PackageReadmeFile=${{ github.workspace }}/README.md `
         -p:PackageLicenseExpression=Apache-2.0
 
     - name: Publish to NuGet.org