Add docs about Icon module

Co-authored-by: Dmitrii Kovanikov <[email protected]>

Author: heathhenley

lib/pretty/pretty.mli

@@ -13,6 +13,9 @@ module Doc = Doc
     {!Layout.t} is the output of {!Doc.render} with all the sizes calculated. *)
 module Layout = Layout
 
+(** Icons and symbols used for identifying different parts. Symbols from Hack Nerd Font Mono are used when it's available. Symbols list:
+
+- https://www.nerdfonts.com/cheat-sheet *)
 module Icon = Icon
 
 (** Render a document into the final string