Post estimated reading time next to the article/post length

Basically, convert Article: 5234 words to Article: 5234 words, 23 minutes.

Not much to explain, I'm lazy and I don't like to do math just to see how much time it would take me to read an article, it would be great to have an estimate similar to how Medium does it. It doesn't have to be as precise, a rough estimate would do the job, for my example I divided the number of words by the average WPM for the english language (228±30 according to Wikipedia).

Additionally, a setting can be added to set a personal reading speed.