About and Installation sections added

We added an About section, which describes the project summarily. In addition, the Installation section replicates with a little more detail the information already present in the Readme file of the 1.0 release.

Ariadne website opens

We are happy to announce that the website for the Ariadne C++ library has opened. We will progressively add content to the site, with the objective of providing references, tutorials, API docs and selected publications.