Hello I see the RSS comes in Vivaldi as in Google Chrome. I do not understand that. I would like it to be as in Mozilla Firefox. There one can put the feed directly in address bar and read the stuff given without clicking more.. If you put this url in Vivaldi or Google Chrome it is not readable: http://www.palestinechronicle.com/feed/ Also there in Mozilla can be RSS mark on the left of the address bar so one can click on it to find RSS of the website which is in the address bar. Also good in Mozilla to have a post-envelope mark/logo to send a website to a friend.
You can install rss detector from the opera add-ons site, which does exactly what you want. Smart rss is a decent reader if you need that too.
To install you need to click on "add to opera" and then on "just get it anyway". This will download the extension to your downloads folder. Then change the suffix from .nex to .crx and drag/drop it on Vivaldi extensions page.