Typically the way to do this — especially on the web — is not with Unicode but with something like FontAwesome. See the request here: Icon request: Julia · Issue #14187 · FortAwesome/Font-Awesome · GitHub
We also have custom emoji here with :julia: 
And see also the thread for LaTeX: Is there a Julia Latex "symbol"? So Latex in Latex is `\LaTeX{}`, is there somethi