Add LICENSING.md (#2029)

Author: romain-gaillard

LICENSING.md

@@ -0,0 +1,13 @@
+# Licensing
+
+License names used in this document are as per [SPDX License List](https://spdx.org/licenses/).
+
+The default license for this project is [Apache-2.0](LICENSE).
+
+## MIT
+
+The following files are licensed under MIT:
+
+```
+internal/component/loki/secretfilter/gitleaks.toml
+```