Revert "rm unused field from WeaveDoc"

This reverts commit 301f9b2f27.

src/run.jl

@@ -58,6 +58,7 @@ function run_doc(
     # This is needed for latex and should work on all output formats
     @static Sys.iswindows() && (fig_path = replace(fig_path, "\\" => "/"))
 
+    doc.fig_path = fig_path
     set_rc_params(doc, fig_path, fig_ext)
 
     # New sandbox for each document with args exposed

src/types.jl

@@ -15,6 +15,7 @@ mutable struct WeaveDoc
     template::Union{AbstractString,Mustache.MustacheTokens}
     css::AbstractString
     highlight_theme::Type{<:Highlights.AbstractTheme}
+    fig_path::AbstractString
     chunk_defaults::Dict{Symbol,Any}
 end