Lua module: make Header argument order consistent

Attributes are always passed as the last element, making it possible to
omit this argument.  Argument order for `Header` was wrong and is fixed.

data/pandoc.lua

@@ -265,12 +265,12 @@ M.Div = M.Block:create_constructor(
 --- Creates a block quote element.
 -- @function Header
 -- @tparam      int          level       header level
--- @tparam      Attributes   attributes  element attributes
 -- @tparam      {Inline,...} content     inline content
+-- @tparam      Attributes   attributes  element attributes
 -- @treturn     Block                    header element
 M.Header = M.Block:create_constructor(
   "Header",
-  function(level, attributes, content)
+  function(level, content, attributes)
     return {c = {level, attributes, content}}
   end,
   {"level", {"identifier", "classes", "attributes"}, "content"}

src/Text/Pandoc/Lua/StackInstances.hs

@@ -173,7 +173,7 @@ pushBlock lua = \case
   CodeBlock attr code      -> pushViaConstructor lua "CodeBlock" code (LuaAttr attr)
   DefinitionList items     -> pushViaConstructor lua "DefinitionList" items
   Div attr blcks           -> pushViaConstructor lua "Div" blcks (LuaAttr attr)
-  Header lvl attr inlns    -> pushViaConstructor lua "Header" lvl (LuaAttr attr) inlns
+  Header lvl attr inlns    -> pushViaConstructor lua "Header" lvl inlns (LuaAttr attr)
   HorizontalRule           -> pushViaConstructor lua "HorizontalRule"
   LineBlock blcks          -> pushViaConstructor lua "LineBlock" blcks
   OrderedList lstAttr list -> pushViaConstructor lua "OrderedList" list lstAttr