minor #12768 Clarified the two main types of exceptions thrown in HttpClient (Toflar)

This PR was merged into the 4.4 branch.

Discussion
----------

Clarified the two main types of exceptions thrown in HttpClient

As learned from @nicolas-grekas in symfony/symfony#34837.
I guess it's worth clarifying it a little bit :)

Commits
-------

d815202 Clarified the three main types of exceptions thrown in HttpClient

Author: javiereguiluz

components/http_client.rst

@@ -436,7 +436,8 @@ Handling Exceptions
 
 When the HTTP status code of the response is in the 300-599 range (i.e. 3xx,
 4xx or 5xx) your code is expected to handle it. If you don't do that, the
-``getHeaders()`` and ``getContent()`` methods throw an appropriate exception::
+``getHeaders()`` and ``getContent()`` methods throw an appropriate exception, all of
+which implement the :class:`Symfony\\Contracts\\HttpClient\\Exception\\HttpExceptionInterface`::
 
     // the response of this request will be a 403 HTTP error
     $response = $client->request('GET', 'https://httpbin.org/status/403');
@@ -477,6 +478,17 @@ errors, exceptions will notify you when needed. On the other hand, if you write
 the error-handling code, you will opt-out from these fallback mechanisms as the
 destructor won't have anything remaining to do.
 
+There are three types of exceptions:
+
+* Exceptions implementing the :class:`Symfony\\Contracts\\HttpClient\\Exception\\HttpExceptionInterface` are thrown when
+  your code does not handle the status codes in the 300-599 range.
+
+* Exceptions implementing the :class:`Symfony\\Contracts\\HttpClient\\Exception\\TransportExceptionInterface` are thrown
+  when a lower level issue occurs.
+
+* Exceptions implementing the :class:`Symfony\\Contracts\\HttpClient\\Exception\\DecodingExceptionInterface` are thrown
+  when a content-type cannot be decoded to the expected representation.
+
 Concurrent Requests
 -------------------