Update README

Author: b8raoult

README.md

@@ -1,5 +1,11 @@
 # ai-models
 
+**DISCLAIMER**
+This project is **BETA** and will be **Experimental** for the foreseeable future.
+Interfaces and functionality are likely to change, and the project itself may be scrapped.
+**DO NOT** use this software in any project/software that is operational.
+
+
 The `ai-models` command is used to run AI-based weather forecasting models. These models need to be installed independently.
 
 ## Usage
@@ -195,3 +201,25 @@ It has the following options:
 - `--expver EXPVER`: The experiment version of the model output.
 - `--class CLASS`: The 'class' metadata of the model output.
 - `--metadata KEY=VALUE`: Additional metadata metadata in the model output
+
+## License
+
+```
+Copyright 2022, European Centre for Medium Range Weather Forecasts.
+
+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.
+
+In applying this licence, ECMWF does not waive the privileges and immunities
+granted to it by virtue of its status as an intergovernmental organisation
+nor does it submit to any jurisdiction.
+```