Add note about the loading time

Author: jtpio

web/pandas/getting_started.md

@@ -5,6 +5,8 @@
 You can try `pandas` in your browser with the following interactive shell
 without installing anything on your computer.
 
+*Note it can take up to 30 seconds before the shell finishes loading and is ready to run commands.*
+
 <iframe
   src="./lite/repl/index.html?toolbar=1&kernel=python&code=import%20pandas%20as%20pd&code=df%20=%20pd.DataFrame(%7B'num_legs':%20%5B2,%204%5D,%20'num_wings':%20%5B2,%200%5D%7D,%20index=%5B'falcon',%20'dog'%5D)"
   width="100%"