Support "Instapaper Text bookmarklet" function

[Mno-hime]

https://www.instapaper.com/save provides two bookmarklets, the first saves to Instapaper, the second one just alters the page so it's easier to read, w/o adding it to Instapaper. It is similar to Read Mode (which is aligned to Pocket) from Firefox 38.0.5 on, it also just removes bloat from the page, the article body is what remains. I'd suggest to place the appropriate button to address bar where "Enter Reader Mode" is placed as well.

Instapaper icons https://staticinstapaper.s3.amazonaws.com/img/ipicons.png for inspiration.