Update path for include-code-files.lua filter style CodeBlocks

This improves the usage of include-files.lua filter in combination
with the include-code-files.lua

Author: lmunch

include-files/include-files.lua

@@ -40,6 +40,14 @@ local function update_contents(blocks, shift_by, include_path)
         image.src = path.normalize(path.join({include_path, image.src}))
       end
       return image
+    end,
+    -- Update path for include-code-files.lua filter style CodeBlocks
+    CodeBlock = function (cb)
+      if cb.attributes.include and path.is_relative(cb.attributes.include) then
+        cb.attributes.include =
+          path.normalize(path.join({include_path, cb.attributes.include}))
+        end
+      return cb
     end
   }