Update faq about changing project slugs (#12184)

Closes #11239

Add a note about redirects. :)

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Signed-off-by: Pavithra Eswaramoorthy <[email protected]>

Author: pavithraes

docs/user/faq.rst

@@ -190,6 +190,9 @@ You can delete and re-create the project with the proper name to get a new slug,
 but you really shouldn't do this if you have existing inbound links,
 as it `breaks the internet <http://www.w3.org/Provider/Style/URI.html>`_.
 
+Instead, you can consider *migrating your documentation to another domain*
+with :doc:`/user-defined-redirects`.
+
 If that isn't enough,
 you can request the change sending an email to [email protected].