Simplify the explanation

Author: javiereguiluz

string.rst

@@ -651,28 +651,20 @@ actual emoji thanks to the :ref:`emojify filter <reference-twig-filter-emojify>`
 
 .. code-block:: twig
 
-    {{ 'I :green-heart: this'|emojify }}                  {# renders: I 💚 this #}
-    {{ ':green_salad: is nice'|emojify('slack') }}        {# renders: 🥗 is nice #}
-    {{ 'My :turtle: has no name yet'|emojify('github') }} {# renders: My 🐢 has no name yet #}
-    {{ ':kiwi: is a great fruit'|emojify('gitlab') }}     {# renders: 🥝 is a great fruit #}
-
-    {{ 'My :turtle: loves to eat :green_salad:'|emojify('slack') }}
-    {# renders: My 🐢 loves to eat 🥗 #}
+    {{ 'I like :kiwi-fruit:'|emojify }} {# renders: I like 🥝 #}
+    {{ 'I like :kiwi:'|emojify }}       {# renders: I like 🥝 #}
+    {{ 'I like :kiwifruit:'|emojify }}  {# renders: I like 🥝 #}
 
-If you are not sure about how the emojis were transliterated, you can use the
-:ref:`text catalog <string-text-emoji>`, which merges the emoji text codes of
-all services:
+By default, ``emojify`` uses the :ref:`text catalog <string-text-emoji>`, which
+merges the emoji text codes of all services. If you prefer, you can select a
+specific catalog to use:
 
 .. code-block:: twig
 
-    {{ 'I like :kiwi-fruit:'|emojify('text') }} {# renders: I like 🥝 #}
-    {{ 'I like :kiwi:'|emojify('text') }}       {# renders: I like 🥝 #}
-    {{ 'I like :kiwifruit:'|emojify('text') }}  {# renders: I like 🥝 #}
-
-.. tip::
-
-    The ``text`` catalog is used by default when no catalog is passed, so calling
-    ``|emojify('text')`` is the same as calling ``|emojify``.
+    {{ 'I :green-heart: this'|emojify }}                  {# renders: I 💚 this #}
+    {{ ':green_salad: is nice'|emojify('slack') }}        {# renders: 🥗 is nice #}
+    {{ 'My :turtle: has no name yet'|emojify('github') }} {# renders: My 🐢 has no name yet #}
+    {{ ':kiwi: is a great fruit'|emojify('gitlab') }}     {# renders: 🥝 is a great fruit #}
 
 Removing Emojis
 ~~~~~~~~~~~~~~~