docs: update README.md

Author: bfabio

README.md

@@ -3,18 +3,11 @@
 [![Join the #publiccode channel](https://img.shields.io/badge/Slack%20channel-%23publiccode-blue.svg?logo=slack)](https://developersitalia.slack.com/messages/CAM3F785T)
 [![Get invited](https://slack.developers.italia.it/badge.svg)](https://slack.developers.italia.it/)
 
-This is a Go, web interface validator for [publiccode.yml](https://github.com/italia/publiccode.yml) files, using [publiccode-parser-go](https://github.com/italia/publiccode-parser-go).
+A RESTful API for validating [publiccode.yml](https://github.com/italia/publiccode.yml)
+files, using the [publiccode-parser-go](https://github.com/italia/publiccode-parser-go)
+library.
 
-publiccode.yml is an international standard for describing public software. It is expected to be published in the root of open source repositories. This parser performs syntactic and semantic validation according to the official spec.
-
-## Features
-
-See related project for details: [publiccode-parser-go](https://github.com/italia/publiccode-parser-go)
-
-
-## Validation from command line
-
-The repository also contains a tool used to validate publiccode.yml files locally.
+## Usage
 
 ```bash
 go run main.go
@@ -24,40 +17,12 @@ curl -X POST "http://localhost:3000/v1/validate"
   --data-binary "@./publiccode.yml"
 ```
 
-## Docker support
-
-The repository has a *Dockerfile*, used to also build the production image, and a *docker-compose.yml* file to facilitate the local deployment.
-
-To build the container, run:
-
-```shell
-docker-compose up [-d] [--build]
-```
-
-where:
-
-* *-d* execute the containers in background
-
-* *--build* forces the containers build
-
-To destroy the container, use:
-
-```shell
-docker-compose down
-```
-
-
 ## Contributing
 
 Contributing is always appreciated.
 Feel free to open issues, fork or submit a Pull Request.
 If you want to know more about how to add new fields, check out [CONTRIBUTING.md](CONTRIBUTING.md). In order to support other country-specific extensions in addition to Italy some refactoring might be needed.
 
-## See also
-
-* [Developers Italia backend & crawler](https://github.com/italia/developers-italia-backend) - a Go crawler for PC.
-* [publiccode-parser-go](https://github.com/italia/publiccode-parser-go) - a Go parser and validator for publiccode.yml files.
-
 ## Maintainers
 
 This software is maintained by community maintainers.
@@ -66,5 +31,5 @@ This software is maintained by community maintainers.
 
 © 2018-2020 Team per la Trasformazione Digitale - Presidenza del Consiglio dei Minstri
 
-Licensed under the EUPL.
+Licensed under AGPL-3.0.
 The version control system provides attribution for specific lines of code.