Update workflows.yaml

Author: genaray

.github/workflows/workflows.yaml

@@ -136,7 +136,10 @@ jobs:
       # Patch csproj temporary to include the package readme
       - name: Patch .csproj for README.md
         run: |
-          echo '  <ItemGroup><None Include="README.md" Pack="true" PackagePath="" /></ItemGroup>' >> src/Arch/Arch.csproj
+          sed -i '/<\/Project>/i \
+          <ItemGroup>\n\
+            <None Include="README.md" Pack="true" PackagePath=\"\" />\n\
+          </ItemGroup>' src/Arch/Arch.csproj
 
       # Restore 
       - name: Restore dependencies