doc(readme): add information about testing and license

Author: mcatta

README.md

@@ -1,2 +1,35 @@
 # diffida
 Rust application based on schnorrkel verification
+
+### Local testing
+This application is hosted on [https://www.shuttle.rs/](https://www.shuttle.rs/) if you want to test it locally you can run:
+```sh
+❯ cargo shuttle run
+```
+
+### Endpoints
+All details are also avaialble calling the `/doc` method
+
+| Endpoint | Description |
+|---|---|
+| `/doc` | Return the swagger API definition in text/plain |
+| `/api/generate` | Generates mnemonic |
+| `/api/sign` | Sign your message |
+| `/api/verify` | Verify your message |
+
+### License
+```
+Copyright 2023 Marco Cattaneo  
+ 
+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  
+ 
+     https://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.
+```