Punctuation corrections.

Included is a reversion of Peter's extra comma (7abfc0108a7b7) that
makes it look like four formats not three.
Consistent style for headings

The style manual does not say which to use.  Looking at the introductory
booklet created by the editorial team, only the first word (apart from
names) begins with a capital.  The main thing is to be consistent.
Starlink Project was our name.
Refactored TABLE section.

Since the original first paragraph was written by Tim without
knowledge of the CHI/tbl format, and the original note requested a
writeup of the tabular format created bt FITS2NDF, that's what I did.
This is an attempt to meld the two parts in a more-cohesive way.
It probably needs another iteration.

The actual extended TABLE format made by FITS2NDF is now described and
illustrated in an appendix.
Fix a few typos.