Merge branch '5.1'

* 5.1:
  [Process] Update process.rst

Author: javiereguiluz

components/process.rst

@@ -392,10 +392,9 @@ instead::
 Using a Prepared Command Line
 -----------------------------
 
-You can run the process by using a a prepared command line using the
-double bracket notation. You can use a placeholder in order to have a
-process that can only be changed with the values and without changing
-the PHP code::
+You can run a process by using a prepared command line with double quote
+variable notation. This allows you to use placeholders so that only the
+parameterized values can be changed, but not the rest of the script:
 
     use Symfony\Component\Process\Process;