Start Issue documentation.

README.md

@@ -25,6 +25,7 @@ Features
 - Configurable error reporter
 - Backtrace with filterable and identifiable frames
 - File preview
+- Supports nested exceptions
 - HTML error report template with light and dark themes
 - Configurable PHP error handler
 - Configurable PHP exception handler
@@ -38,7 +39,8 @@ The package provides 2 components to help you interact with PHP errors and excep
     - [Reporters](#reporters)
     - [PHP Error Handler](#php-error-handler)
     - [PHP Exception Handler](#php-exception-handler)
-2. [Backtrace](#backtrace)
+2. [Issue](#issue)
+3. [Backtrace](#backtrace)
 
 Report Handler
 --------------
@@ -222,13 +224,13 @@ $reportHandler = new ReportHandler(
 set_error_handler(new ErrorHandler($reportHandler));
 ```
 
-The `ErrorHandler` captures all triggered PHP errors. The current implementation is only reporting the **deprecated** errors (E_DEPRECATED, E_USER_DEPRECATED) with the given `ReportHandler` instance. All other errors are converted to an `ErrorException` and are thrown so the default PHP exception handler can capture them.
+The `ErrorHandler` class captures all triggered PHP errors. The current implementation is only reporting the **deprecated** errors (E_DEPRECATED, E_USER_DEPRECATED) with the given `ReportHandler` instance. All other errors are converted to an `ErrorException` and are thrown back again so the default PHP exception handler can capture them.
 
 ### PHP Exception Handler
 
 You can register a `ReportHandler` instance as the default PHP exception handler. See the [set_exception_handler()](https://www.php.net/manual/en/function.set-exception-handler.php) function in the PHP documentation for details.
 
-Just like for the PHP errors, the package provides a pre-configured class can be register a `ReportHandler` instance and hook it up as the default PHP exception handler.
+Just like for the PHP errors, the package provides a pre-configured class that requires a `ReportHandler` instance and hook it up as the default PHP exception handler.
 Simply pass an `ExceptionHandler` class instance to the `set_exception_handler` PHP function like so:
 
 ```php
@@ -244,7 +246,7 @@ set_exception_handler(new ExceptionHandler($reportHandler));
 
 #### HTML Error Report Template
 
-On a web context, you might want to render thrown exceptions in the browser during development to easily debug your application. The package also provides a HTML template with a light and a dark theme. Here is an example on how to use the `ExceptionHandlerHttpResponse` class that is responsible to prepare the data for usage in the `resources/views/exception.php` file from this package:
+On a web context, you might want to render thrown exceptions in the browser, during development, to easily debug your application. The package provides a HTML template with a light and a dark theme. Here is an example on how to use the `ExceptionHandlerHtmlResponse` class, responsible to render a given `Issue` as HTML to the `stdout`:
 
 ```php
 <?php
@@ -256,9 +258,16 @@ $reporters->add(
         $backtrace = new Backtrace(new InMemoryFrameIdentifiers());
         $backtrace->captureException($issue->exception());
 
-        (new ExceptionHandlerHttpResponse(
+        $information = new InMemoryInformation();
+        $information->add(
+            (new InformationGroup('General'))
+                ->add('PHP', phpversion())
+                ->add('OS', php_uname('s'))
+        );
+
+        (new ExceptionHandlerHtmlResponse(
             backtrace: $backtrace,
-            information: new InMemoryInformation(),
+            information: $information,
         ))->render($issue);
     }),
 );
@@ -271,9 +280,32 @@ $reportHandler = new ReportHandler(
 set_exception_handler(new ExceptionHandler($reportHandler));
 ```
 
-The above code snippet is attaching a `ReportHandler` to the default PHP exception handler. The report handler contains one reporter that is exposing any thrown exceptions to the standard output using HTML.
+The above code snippet is attaching a `ReportHandler` to replace the default PHP exception handler. The report handler contains one reporter that is exposing any thrown exceptions to the standard output using HTML.
 
 > The attached condition is to always report the issue to the stdout. On your application, make sure to constraint the condition to avoid rendering the error HTML template on a production environment.
 
+Issue
+-----
+
+An `Issue` is the package abstract definition for any problem that could occur inside a PHP application. The `ReportHandler` is never directly dealing with a PHP error nor a PHP exception but with an `Issue` instance.
+
+An issue contains the following properties:
+
+- A message: the problem description text.
+- A date: when the problem occurred.
+- A level: the severity of the issue, following PSR-3 levels.
+- An exception: for PHP compatibity, the issue should be able to be converted/translated to an exception.
+- Information: any additional information about the issue.
+
+In most PHP applications, developers have to deal with exceptions. The package provides the `ExceptionalIssue` class that can be used to translate an exception into an issue like so:
+
+```php
+<?php
+
+$issue = ExceptionalIssue::create(new RuntimeException('Oops!'));
+```
+
+### Information
+
 Backtrace
 ---------