minor #16984 [Notifier] Add ContactEveryone Doc (zairigimad)

This PR was squashed before being merged into the 6.2 branch.

Discussion
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[Notifier] Add ContactEveryone Doc

fix issue : #16915
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Commits
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08e8319 [Notifier] Add ContactEveryone Doc

Author: javiereguiluz

notifier.rst

@@ -66,6 +66,7 @@ Service         Package                               DSN
 AllMySms        ``symfony/all-my-sms-notifier``       ``allmysms://LOGIN:APIKEY@default?from=FROM``
 AmazonSns       ``symfony/amazon-sns-notifier``       ``sns://ACCESS_KEY:SECRET_KEY@default?region=REGION``
 Clickatell      ``symfony/clickatell-notifier``       ``clickatell://ACCESS_TOKEN@default?from=FROM``
+ContactEveryone  ``symfony/contact-everyone-notifier`` ``contact-everyone://TOKEN@default?&diffusionname=DIFFUSION_NAME&category=CATEGORY``  
 Esendex         ``symfony/esendex-notifier``          ``esendex://USER_NAME:PASSWORD@default?accountreference=ACCOUNT_REFERENCE&from=FROM``
 FakeSms         ``symfony/fake-sms-notifier``         ``fakesms+email://MAILER_SERVICE_ID?to=TO&from=FROM`` or ``fakesms+logger://default``
 FreeMobile      ``symfony/free-mobile-notifier``      ``freemobile://LOGIN:PASSWORD@default?phone=PHONE``