[C#] Add packaging artifacts to build a .nuget zip

[ldk-java] / c_sharp / packaging_artifacts / LICENSE-APACHE

diff --git a/c_sharp/packaging_artifacts/LICENSE-APACHE b/c_sharp/packaging_artifacts/LICENSE-APACHE
new file mode 120000 (symlink)
index 0000000..1cd601d
--- /dev/null
+++ b/c_sharp/packaging_artifacts/LICENSE-APACHE
@@ -0,0 +1 @@
+../../LICENSE-APACHE
\ No newline at end of file