Feature Request

Is your feature request related to a problem or unsupported use case? Please describe.
In some product as outline, or Grist, if we place an emoji at the beginning of the title of a subpage (or sometimes even on the main page), then the basic page icone will be changed for this emoji in the tree structure.

Describe the solution you'd like
Some users would like that if they put an emoji at the beginnong of the title, then the basic page icon is changed for the emoji in the tree structure.