hdf5doc

Description:
html/index.html                                                  18 189 19
    Update "Technical Notes" description.
html/TechNotes.html                                              18 189 19
    Label top section "Special Topics."
    Label bottom section "Technical Notes and Historical Notes."
    Modify introductory text.
    Modify formatting, in part to smooth window resizing.
    Clean up HTML and minor copy edits.
Tested:  Firefox