fix warning in available_marker_symbols

available_marker_symbols() was not highlighted as code, resulting in a warning that had underlined the word marker

src/conversions.jl

@@ -1922,7 +1922,7 @@ function to_spritemarker(marker::Symbol)
     if haskey(default_marker_map(), marker)
         return to_spritemarker(default_marker_map()[marker])
     else
-        @warn("Unsupported marker: $marker, using ● instead. Available options can be printed with available_marker_symbols()")
+        @warn("Unsupported marker: $marker, using ● instead. Available options can be printed with `available_marker_symbols()`")
         return '●'
     end
 end
@@ -1985,4 +1985,4 @@ GeometryBasics.collect_with_eltype(::Type{T}, vec::ShaderAbstractions.Buffer{T})
 # Used in Label, maybe useful elsewhere?
 to_lrbt_padding(x::Real) = Vec4f(x)
 to_lrbt_padding(xy::VecTypes{2}) = Vec4f(xy[1], xy[1], xy[2], xy[2])
-to_lrbt_padding(pad::VecTypes{4}) = to_ndim(Vec4f, pad, 0)
+to_lrbt_padding(pad::VecTypes{4}) = to_ndim(Vec4f, pad, 0)