added more descriptive instructions for users. Clearer that they must use three different methods to add a class

Improved instructions for users to see that they must use three different ways to add a class

Added clearer instructions to JQuery/Json challenge

added closing tags to button and em

spelling fix

possbile => possible

challenges/01-front-end-development-certification/jquery.json

@@ -344,10 +344,12 @@
       "title": "Target the same element with multiple jQuery Selectors",
       "description": [
         "Now you know three ways of targeting elements: by type: <code>$(\"button\")</code>, by class: <code>$(\".btn\")</code>, and by id <code>$(\"#target1\")</code>.",
+        "Although it is possible to add multiple classes in a single <code>.addClass()</code> call, let's add them to the same element in <em>three separate ways</em>.",
         "Using <code>.addClass()</code>, add only one class at a time to the same element, three different ways:",
         "Add the <code>animated</code> class to all elements with type <code>button</code>.",
         "Add the <code>shake</code> class to all the buttons with class <code>.btn</code>.",
-        "Add the <code>btn-primary</code> class to the button with id <code>#target1</code>."
+        "Add the <code>btn-primary</code> class to the button with id <code>#target1</code>.",
+        "<strong>Note</strong><br>You should only be targeting one element and adding only one class at a time. Altogether, your three individual selectors will end up adding the three classes <code>shake</code>, <code>animated</code>, and <code>btn-primary</code> to <code>#target1</code>."
       ],
       "challengeSeed": [
         "fccss",