feature requests : )

[gospodinBezkrai]

Thank you very much for so quick upgrade on the shortcuts!

After some more natural use of the add-on, I could suggest a few more small things for your consideration.
I ordered them according to importance for my own subjective use.

• Sometimes Sci-hub does a 'not a robot' check (esp. the .st website) but the outcome for the add-on is to report that the paper was not found and go to Library STC. Is it possible to add a button or some other onClick ability on the information tooltip? In case I want to check for myself why no result was found - it would open Sci-hub and let the user take it from there. Perhaps copying the DOI to the clipboard would also be convenient.
  [This would also help users debug when something doesn't work - e.g. pt. 3 below.]

• For me Library STC doesn't load the pdf pages and I can't really use it (probably something to do with the country I am in). This doesn't concern the add-on, but it would be convenient if in the options we could put a checkmark on each service whether we want it on or off.

• Any time I tried in Google Books, I got 'Not found in Open Library' but clearly there is some other problem.

• The DOIs on this journal publisher website don't get found:
  https://academic.oup.com/joc/article-abstract/61/5/959/4098493

• A major publisher of books which Google Scholar points to these days instead of Google Books is Taylor&Francis.
  It does contain a DOI on the page, but the books won't be in Sci-Hub, rather in LibGen.
  Here are two examples:
  https://www.taylorfrancis.com/books/edit/10.4324/9781003572923/new-critical-writings-political-sociology-alan-scott-kate-nash
  https://www.taylorfrancis.com/books/mono/10.4324/9780203854693/media-effects-society-jennifer-lambe-elizabeth-perse
  [Interestingly, books by Springer get found in Sci-hub!]

• The state of the option about tabs is not 'remembered' when I open preferences, and if I don't notice, the add-on reverts to opening in new tabs.

In any case it has already saved me a lot of clicking time in the last few weeks, as I was reading into a new field!

[Factual0367]

Thanks for the suggestions! Will implement them when I get a chance.