Word count and reading time estimation for GROQ and Portable Text

*[
  _type == "post"
]{
  title,
  "numberOfCharacters": length(pt::text(body)),
  // assumes 5 characters as mean word length
  // https://ux.stackexchange.com/questions/22520/how-long-does-it-take-to-read-x-number-of-characters
  "estimatedWordCount": round(length(pt::text(body)) / 5),
  // Words per minute: 180
  "estimatedReadingTime": round(length(pt::text(body)) / 5 / 180 )
}

{
  "wpm": 180,
  "meanWordCharacterCount": 5
}
{  
  "posts": *[_type == "post"]
  	{
  		...,
		  "numberOfCharacters": length(pt::text(body))
		}
		{	
      title,
  	  "estimatedWordCount": round(numberOfCharacters / ^.^.meanWordCharacterCount),
  		"estimatedReadingTime": round(numberOfCharacters / ^.^.meanWordCharacterCount / ^.^.wpm)
		}
}