Update tool which generates lua module docs

All "helper functions" are not part of the Lua code for module pandoc,
but are added in Haskell. The respective documentation section must
therefore be excluded from automatic regeneration.

doc/lua-filters.md

@@ -1323,7 +1323,7 @@ Lua functions for pandoc scripts.
 
     See also: [OrderedList](#OrderedList)
 
-## Helper Functions
+## Helper functions
 
 [`pipe (command, args, input)`]{#pipe}
 
@@ -1346,8 +1346,7 @@ Lua functions for pandoc scripts.
 
 [`walk_block (element, filter)`]{#walk_block}
 
-:   Apply a filter inside a block element, walking its
-    contents.
+:   Apply a filter inside a block element, walking its contents.
 
     Parameters:
 
@@ -1355,8 +1354,8 @@ Lua functions for pandoc scripts.
     :   the block element
 
     `filter`:
-    :   a lua filter (table of functions) to be applied
-        within the block element
+    :   a lua filter (table of functions) to be applied within
+        the block element
 
     Returns: the transformed block element
 
@@ -1371,8 +1370,8 @@ Lua functions for pandoc scripts.
     :   the inline element
 
     `filter`:
-    :   a lua filter (table of functions) to be applied
-        within the inline element
+    :   a lua filter (table of functions) to be applied within
+        the inline element
 
     Returns: the transformed inline element
 
@@ -1399,7 +1398,6 @@ Lua functions for pandoc scripts.
         -- The inline element in that block is an `Emph`
         assert(block.content[1].t == "Emph")
 
-
 # Module pandoc.utils
 
 This module exposes internal pandoc functions and utility

tools/update-lua-docs.lua

@@ -25,7 +25,9 @@ end
 
 function Header (el)
   if in_module_section then
-    if el.level == 1 then
+    if el.level == 1 or
+       -- special case for Module pandoc
+       (el.level == 2 and el.identifier == 'helper-functions') then
       in_module_section = false
       return el
     else