Feature: add duration of article after adding

Hello,

I just had this idea that it would be great to display the reading time duration when adding an article is successful.
In my case it's because I add a lot of articles at once and read them later, and if some are short I might want to read them right away.

Thanks

No files, tests, or entry points are named. Trace the successful article-add flow in the browser extension, determine where the article response and reading duration are available, and confirm the completed behavior by adding an article and checking that its duration is displayed.

Written by the indexing model from the issue text.