update licensing

Author: codengine

LICENSE

@@ -199,4 +199,11 @@
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
-   limitations under the License.
+   limitations under the License.
+
+
+   Third-party libraries are licensed as followed:
+   - Adlib Gold: Personal permission granted by John Novak from DosBox Staging
+   - Nuked-OPL3: LGPL-2.1
+   - iir1: MIT
+   - YM7128B_emu: BSD 2-Clause

src/Spice86.Libs/Sound/Devices/AdlibGold/README.md

@@ -0,0 +1,5 @@
+A special personal permission to port this component from DosBox was issued by John Novak, project lead of DosBox
+Staging,
+who also created the source of this device.
+
+Many thanks for the great work and the DosBox Staging project by itself!