Restored the versionadded directives partially

Author: javiereguiluz

components/http_client.rst

@@ -9,6 +9,10 @@ The HttpClient Component
     PHP stream wrappers and cURL. It provides utilities to consume APIs and
     supports synchronous and asynchronous operations.
 
+.. versionadded:: 4.3
+
+    The HttpClient component was introduced in Symfony 4.3.
+
 Installation
 ------------
 

components/mailer.rst

@@ -7,6 +7,10 @@ The Mailer Component
 
     The Mailer component helps sending emails.
 
+.. versionadded:: 4.3
+
+    The Mailer component was introduced in Symfony 4.3.
+
 Installation
 ------------
 

components/mime.rst

@@ -9,6 +9,10 @@ The Mime Component
     The Mime component allows manipulating the MIME messages used to send emails
     and provides utilities related to MIME types.
 
+.. versionadded:: 4.3
+
+    The Mime component was introduced in Symfony 4.3.
+
 Installation
 ------------
 

mailer.rst

@@ -1,6 +1,11 @@
 Sending Emails with Mailer
 ==========================
 
+.. versionadded:: 4.3
+
+    The Mailer component was introduced in Symfony 4.3. The previous solution,
+    called Swift Mailer, is still valid: :doc:`Swift Mailer</email>`.
+
 Installation
 ------------