minor #16695 [ExpressionLanguage] Add some more operators (zairigimad)

This PR was merged into the 6.1 branch.

Discussion
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[ExpressionLanguage] Add some more operators

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fix: #16677

Commits
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e33b43f Update syntax.rst

Author: javiereguiluz

components/expression_language/syntax.rst

@@ -210,6 +210,9 @@ Comparison Operators
 * ``<=`` (less than or equal to)
 * ``>=`` (greater than or equal to)
 * ``matches`` (regex match)
+* ``contains``
+* ``starts with``
+* ``ends with``
 
 .. tip::