Update html_updateHeadings.sh.
    
        - Heading update works but commented in this commit.
    
        - Table of content construction is still unfunctional.  I've got
          frustrated by now trying to make it functional using one
          dimensional array. Create a numerical identification using
          counter, level, parent and link for each line to see if I can do
          with awk. Don't know if possible, but will try.