Display a single achievement inline.
Preview:

Attributes:
- id – The ID of the achievement to render.
- link – Add a link on achievement title to the achievement page. Accepts:
yesornoDefault:yes - thumbnail – Display the achievement featured image. Accepts:
yesornoDefault:yes - thumbnail_size – The achievement featured image size in pixels. Leave empty to use the image size from settings.
Example:
[gamipress_inline_achievement id="1" link="yes" thumbnail="yes" thumbnail_size="24"]