Update docs examples so they don't use deprecated features, styling tweaks (#982)

* Deprecate pyscript output attribute

* Update code blocks so they work

* Small tweaks to styling and use html to warning

* Fix broken test from bad conflict resolution

* lowercase pyodide

docs/reference/modules/pyscript.md

@@ -63,7 +63,7 @@ A proxy for the runtime's `globals()` dictionary. For example:
     <button onclick="showX()">Click Me to Get 'x' from Python</button>
     <script>
         function showX(){
-            console.log(`In Python right now, x = ${PyScript.runtime.globals.get('x')}`)
+            console.log(`In Python right now, x = ${pyscript.runtime.globals.get('x')}`)
         }
     </script>
 </body>