Add an `Edit button` overlay on pages when a user is logged in as an admin/editor

**Is your feature request related to a problem? Please describe.**
When having many (similar) pages on the site, it may not be easy to go into the admin, locate, and edit the exact page you're looking for. This is especially true considering that the slug has no reference to the ID.

**Describe the solution you'd like**
An apparent visual cue should appear on all public pages in a place that does not disturb the user once an admin is logged in.
Other implementations of this feature show an edit button (usually in the bottom-right corner of the page) that takes the user to a screen to edit that page.

**Describe alternatives you've considered**
This can be mitigated with an improved search functionality, which would make the page a lot easier to find by name/slug/etc. But better discoverability is more challenging than allowing a user who is already logged in to the site to go to the edit screen of that page directly from the public website.

**Additional context**
Implementation of this feature in Google Forms