improve usability of icon sizes (was very tiny!)

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | na
| Fixed tickets | na
| Refs tickets  | na
| License       | MIT
| Doc PR        | na

ping @phaidon

icons were unusably small for old folks like me. :smile: