Add a feature to save any question as a prompt

[kickTiger]

Add a button next to any question in the conversation that allows the user to save the question as a prompt. For example, the button could look like the one in the image below

[benf2004]

I like this idea. This can currently be accomplished by using the highlight & right-click function, but that's not as convenient as what you're suggesting. I'll add it to the TODO

[benf2004]

removed in v4