add avatars functionality

[rnewton]

Motivation

Adding functionality use placeholder avatars.

Have you...

• [x] Written a sample in _samples?
• [x] Updated documentation in the docs/ folder?
• [x] Linked this PR to an issue?
• [x] Written any automated tests?
• [x] Refactored your code to be maintainable?

The above things are not required, but appreciated.

[andymeneely]

Oh and don't worry about the CI failure - macos + Ruby3 has been having issues on GHActions lately