add html files with math inside

...bpage/GAP (GAPDoc Example) - Chapter 2: Other Markup.html

...derga) - Chapter 9: The basic theory behind Wedderga.html

...omwebpage/GAP (ref) - Chapter 18: Cyclotomic Numbers.html

...ebpage/GAP (ref) - Chapter 60: Abelian Number Fields.html

...fromwebpage/GAP (ref) - Chapter 71: Character Tables.html