Add description to README.md

Author: devanych

README.md

@@ -1,3 +1,69 @@
 # HTTP Error Handler
 
-The repository is under development, and the description will appear later.
+[![License](https://poser.pugx.org/httpsoft/http-error-handler/license)](https://packagist.org/packages/httpsoft/http-error-handler)
+[![Latest Stable Version](https://poser.pugx.org/httpsoft/http-error-handler/v)](https://packagist.org/packages/httpsoft/http-error-handler)
+[![Total Downloads](https://poser.pugx.org/httpsoft/http-error-handler/downloads)](https://packagist.org/packages/httpsoft/http-error-handler)
+[![GitHub Build Status](https://github.com/httpsoft/http-error-handler/workflows/build/badge.svg)](https://github.com/httpsoft/http-error-handler/actions)
+[![Scrutinizer Code Coverage](https://scrutinizer-ci.com/g/httpsoft/http-error-handler/badges/coverage.png?b=master)](https://scrutinizer-ci.com/g/httpsoft/http-error-handler/?branch=master)
+[![Scrutinizer Code Quality](https://scrutinizer-ci.com/g/httpsoft/http-error-handler/badges/quality-score.png?b=master)](https://scrutinizer-ci.com/g/httpsoft/http-error-handler/?branch=master)
+
+This package implements [Psr\Http\Server\MiddlewareInterface](https://github.com/php-fig/http-server-middleware/blob/master/src/MiddlewareInterface.php) and [Psr\Http\Server\RequestHandlerInterface](https://github.com/php-fig/http-server-handler/blob/master/src/RequestHandlerInterface.php).
+
+## Documentation
+
+* [In English language](https://httpsoft.org/docs/error-handler).
+* [In Russian language](https://httpsoft.org/ru/docs/error-handler).
+
+## Installation
+
+This package requires PHP version 7.4 or later.
+
+```
+composer require httpsoft/http-error-handler
+```
+
+## Usage ErrorHandler
+
+```php
+use HttpSoft\ErrorHandler\ErrorHandler;
+
+/**
+ * @var Psr\Http\Message\ServerRequestInterface $request
+ * @var Psr\Http\Server\RequestHandlerInterface $handler
+ *
+ * @var HttpSoft\ErrorHandler\ErrorListenerInterface $logErrorListener
+ * @var HttpSoft\ErrorHandler\ErrorListenerInterface $sendErrorListener
+ * @var HttpSoft\ErrorHandler\ErrorResponseGeneratorInterface $responseGenerator
+ */
+
+$errorHandler = new ErrorHandler($handler, $responseGenerator);
+
+$errorHandler->addListener($logErrorListener);
+$errorHandler->addListener($sendErrorListener);
+
+/** @var \Psr\Http\Message\ResponseInterface $response */
+$response = $errorHandler->handle($request);
+```
+
+## Usage ErrorHandlerMiddleware
+
+```php
+use HttpSoft\ErrorHandler\ErrorHandlerMiddleware;
+
+/**
+ * @var Psr\Http\Message\ServerRequestInterface $request
+ * @var Psr\Http\Server\RequestHandlerInterface $handler
+ *
+ * @var HttpSoft\ErrorHandler\ErrorListenerInterface $logErrorListener
+ * @var HttpSoft\ErrorHandler\ErrorListenerInterface $sendErrorListener
+ * @var HttpSoft\ErrorHandler\ErrorResponseGeneratorInterface $responseGenerator
+ */
+
+$errorHandler = new ErrorHandlerMiddleware($responseGenerator);
+
+$errorHandler->addListener($logErrorListener);
+$errorHandler->addListener($sendErrorListener);
+
+/** @var \Psr\Http\Message\ResponseInterface $response */
+$response = $errorHandler->process($request, $handler);
+```