Open an online REPL instead of evaluating only

[tsdh]

First of all, this is a very useful extension!

One enhancement I'd welcome was to be able to evaluate a snipped, but instead of only displaying its result, get an online REPL (like tryclj.org). For example, I evaluate some function definition in some blog posting, and then I can play around with it, e.g., call it with different arguments.