* (i) auto naming attempts to extract a suitable numeric name from document
  headings if available, at times one appears to be available but is re-used
  elsewhere in the document, (as where the document has Parts or Sections and
  naming starts again within these sections from 1); (ii) this is treated as an
  exception and an alternative sequential naming scheme is triggered; (iii) if a
  document heading does not provide a suitable numeric name, another sequential
  scheme is used

* adjustment to (existing) provided feedback, based on:
  * level A~ title, required;
  * levels B~ C~ D~ optional sequential document divider headings
    (Part, Section etc. equivalent);
  * level 1~ required, heading level preceding substantive text; followed by
  * levels 2~ 3~ 4~ optional, sequential headings
    (1.1, 1.1.1, 1.1.1.1 equivalents)

* expansion of sisu output filepaths (sync with use of --act0 to --act9)

* adjustments to default settings for --act0 to --act9 (to match current "se")
* removed sisurc examples to organize output by filetype, filename, monolingual,
  as one word diff
  output_dir_structure_by: language
  # (language|filetype|(filetype_mono|monolingual)|filename|filename_mono)
  # language
  #   (language and filetype directories);
  # filetype
  #   (filetype directories, filename includes language code);
  # filetype_mono (or monolingual)
  #   (filetype drectories, no language codes in filenames)
  # filename
  #   (directory output similar to v1 v2, filename includes language code);
  # filename_mono
  #   (directory output similar to v1 v2, filename without language code)