update license

Author: adizere

README.md

@@ -67,3 +67,18 @@ This demo achieves a throughput of 10MB/s second by finalizing one 10MB block pe
 
 These numbers are from a local network run with 3 validators on a Macbook. However, given that Malachite has been benchmarked in a large distributed network at 13.5MB per second, it is likely that this demo's speed would hold up in that scenario as well.
 
+## License
+
+Copyright 2025 Informal Systems Inc
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+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.