added missing link

src/introduction.md

@@ -0,0 +1,48 @@
+# Futures Explained in 200 Lines of Rust
+
+This book aims to explain `Futures` in Rust using an example driven approach.
+
+The goal is to get a better understanding of `Futures` by implementing a toy
+`Reactor`, a very simple `Executor` and our own `Futures`. 
+
+We'll start off a bit differently than most other explanations. Instead of 
+deferring some of the details about what's special about futures in Rust we 
+try to tackle that head on first. We'll be as brief as possible, but as thorough 
+as needed. This way, most question will be answered and explored up front. 
+
+We'll end up with futures that can run an any executor like `tokio` and `async_str`.
+
+In the end I've made some reader exercises you can do if you want to fix some
+of the most glaring omissions and shortcuts we took and create a slightly better
+example yourself.
+
+> This book is developed in the open, and contributions are welcome. You'll find
+> [the repository for the book itself here][book_repo]. The final example which
+> you can clone, fork or copy [can be found here][example_repo]
+
+## What does this book give you that isn't covered elsewhere?
+
+There are many good resources and examples already. First
+of all, this book will focus on `Futures` and `async/await` specifically and
+not in the context of any specific runtime.
+
+Secondly, I've always found small runnable examples very exiting to learn from. 
+Thanks to [Mdbook][mdbook] the examples can even be edited and explored further. It's
+all code that you can download, play with and learn from.
+
+We'll and end up with an understandable example including a `Future`
+implementation, an `Executor` and a `Reactor` in less than 200 lines of code. 
+We don't rely on any dependencies or real I/O which means it's very easy to 
+explore further and try your own ideas.
+
+
+## Credits and thanks
+
+I'll like to take the chance of thanking the people behind `mio`, `tokio`, 
+`async_std`, `Futures`, `libc`, `crossbeam` and many other libraries which so
+much is built upon.  Even the RFCs that much of the design is built upon is 
+very well written and very helpful. So thanks!
+
+[mdbook]: https://github.com/rust-lang/mdBook
+[book_repo]: https://github.com/cfsamson/books-futures-explained
+[example_repo]: https://github.com/cfsamson/examples-futures