minor #16216 Import jquery as the $ variable. (drew7721)

This PR was submitted for the 5.4 branch but it was merged into the 5.3 branch instead.

Discussion
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Import jquery as the $ variable.

If we want to use the `$` for jQuery we need to import it as such.

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Commits
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3747324 Import jquery as the $ variable.

Author: javiereguiluz

frontend/encore/simple-example.rst

@@ -182,7 +182,7 @@ Great! Use ``import`` to import ``jquery`` and ``greet.js``:
       // ...
 
     + // loads the jquery package from node_modules
-    + import jquery from 'jquery';
+    + import $ from 'jquery';
 
     + // import the function from greet.js (the .js extension is optional)
     + // ./ (or ../) means to look for a local file