Missing "duration to read" on each page

[DerekMelchin]

Expected Behavior

We provide an estimate to the duration to read each page.

Actual Behavior

There is not currently an estimate.

Checklist

• [x] I have completely filled out this template
• [x] I have confirmed that this issue exists on the current master branch
• [x] I have confirmed that this is not a duplicate issue by searching issues