Add example usage to readme

Author: tecosaur

README.md

@@ -8,3 +8,24 @@
 The `JuliaSyntaxHighlighting` package builds on the `StyledStrings` and
 `JuliaSyntax` standard libraries to provide a simple utility for applying syntax
 highlighting to text.
+
+```julia-repl
+julia> using JuliaSyntaxHighlighting: highlight, highlight!
+
+julia> highlight("String(reinterpret(UInt8, [0x293a2061696c756a]))")
+"String(reinterpret(UInt8, [0x293a2061696c756a]))" # Colored in the REPL
+
+julia> Base.annotations(ans)
+11-element Vector{Tuple{UnitRange{Int64}, Pair{Symbol, Any}}}:
+ (1:6, :face => :julia_funcall)
+ (1:6, :face => :julia_type)
+ (7:7, :face => :julia_rainbow_paren_1)
+ (8:18, :face => :julia_funcall)
+ (19:19, :face => :julia_rainbow_paren_2)
+ (20:24, :face => :julia_type)
+ (27:27, :face => :julia_rainbow_bracket_1)
+ (28:45, :face => :julia_number)
+ (46:46, :face => :julia_rainbow_bracket_1)
+ (47:47, :face => :julia_rainbow_paren_2)
+ (48:48, :face => :julia_rainbow_paren_1)
+```