minor #14513 Add priority order explanation for tagged services (hermann8u)

This PR was submitted for the 5.1 branch but it was squashed and merged into the 4.4 branch instead.

Discussion
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Add priority order explanation for tagged services

Hi,

In this page, the priority order is not explained for tagged services. Since I needed to know this, I guess it is a good addition.
The text is mostly inspired by the paragraph about priority in the event dispatcher documentation : https://symfony.com/doc/current/event_dispatcher.html#creating-an-event-listener

Fell free to edit it or to provide me some advices to do it.

Regards

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Commits
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958aeaf Add priority order explanation for tagged services

Author: javiereguiluz

service_container/tags.rst

@@ -596,8 +596,9 @@ Tagged Services with Priority
 
     The ability to prioritize tagged services was introduced in Symfony 4.4.
 
-The tagged services can be prioritized using the ``priority`` attribute,
-thus providing a way to inject a sorted collection of services:
+The tagged services can be prioritized using the ``priority`` attribute.
+The priority is a positive or negative integer. The higher the number,
+the earlier the tagged service will be located in the collection:
 
 .. configuration-block::
 
@@ -655,7 +656,7 @@ service itself::
         }
     }
 
-If you want to have another method defining the priority 
+If you want to have another method defining the priority
 (e.g. ``getPriority()`` rather than ``getDefaultPriority()``),
 you can define it in the configuration of the collecting service: