fix(guide): add warning about a potential security issue (#33221)

guide/english/jquery/jquery-html-method/index.md

@@ -29,6 +29,9 @@ $('p').html('Hello World!');
 
 That will set the content of all of the `<p>` elements to Hello World!
 
+## Warning
+`.html()` method is used to set the element's content in **HTML** format. This may be dangerous if the content is provided by user. Consider using `.text()` method instead if you need to set non-HTML strings as content.
+
 ### More Information
 
 [W3Schools](https://www.w3schools.com/jquery/html_html.asp)