[FR]: Add a button to exchange what is in the find field and the replace field.
Thanks for your time in this awesome plugin.
I always use this plugin to batch adjust the text highlight formats, and sometimes I think it would be great if there is a button to allow us to exchange what is in the find field and the replace field, for quickly achiving a kind of redo process.

This wouldn't work if you actually used a regex. What should happen if you switch find: "hltr-([^"]*)" with replace: "shadow-$1"? Maybe this feature would have some use with plain find/replace, but I don't know that it makes sense in this plugin.
I use this plugin not only when regex is involved and one of my use case is, when using Highlightr to highlight texts with different colors to designate different info types, such a button would help a lot to quickly undo and redo the color change by just exchanging the positions of <mark class="hltr-red"> and <mark class="hltr-yellow">.