Improved the language in the "Exploring OrbTK" section.

Christian Stadelmann authored 8 years ago and Jeremy Soller committed 8 years ago

It looks like virtual terminal usage has changed, so I updated this page. Feel free to correct me if I'm wrong.

The changes include:
- Editing for flow and understandability.
- Unifying how links are included in the source files.
- Adding an `About this Book` page to the introduction.
- Adding a few examples or new pieces of information I felt were
  lacking when I read the book.
- Unifying 'user space' and 'kernel space' spelling.
- Added myself to the authors list in `overview/welcome.md`.

See http://azerupi.github.io/mdBook/format/theme/syntax-highlighting.html