[gtkmm] Please remove the misleading links from the homepage

[Maurizio Colucci <seguso forever tin it>]

Hello,

There is a big flaw in the homepage architecture!

After a week of pain trying to figure out myself how to use the eventbox, I 
click the link "book" and a nice tutorial pops up explaining it.
I had been there before, but  I had closed it without reading it. Then I had 
never come back there, because of the misleading links to chapters of the 
book, in the home page. If you see links "chapters", YOU ASSUME that these 
are the only chapters that are available. You don't imagine that if you click 
"book" you will find more chapters.

Please, if you want to keep the links to those chapters, PLEASE SPECIFY that 
there are more chapters available by clicking the "book" link.

And please, change the name "book" to tutorial. One doesn't click it because 
he thinks it will point to some amazon page.

Maurizio