Changing `cargo install` to `cargo install --path .` prevents the following error:
<span style="color: red;">error:</span> Using `cargo install` to install the binaries for the package in current working directory is no longer supported, use `cargo install --path .` instead. Use `cargo build` if you want to simply build the package.
* Added documentation to the `config` module
* Added an example to the `config` module
* Updated the docs in lib.rs regarding implementing backends
* Started writing an alternate backends walkthrough
* Mentioned the output.foo.command key
* Added example output
* Added a config section to the backends tutorial
* Finished off the backends tutorial
* Made sure travis checks mdbook-wordcount
* Fixed the broken link at in the user guide
* Changed how travis builds the project
* Added a conclusion
* Went through and documented a lot of stuff
* Added a preprocessors chapter and updated For Developers
