[add] new documentation

These are the squashed changes for aggregating most of the documentation found within:

- https://github.com/yaxu/Tidal/blob/master/doc/
- https://github.com/yaxu/Tidal/wiki

Organized into several chapters ranging from _simple_ to _advanced_

1. Getting Started
2. Patterns
3. Reference
4. HowTos
5. Publications

Documentation (written in Markdown) is put into separate folders [using collections](http://jekyllrb.com/docs/collections/) with subfolders for each section within a chapter. Configuration for sections and chapters is found within:

- `_config.yml`
- `_data/chapters.yml`

Introductions to chapters are currently written as top-level Markdown files named after the corresponding chapter with the category key set to the chapter's name.

Introductions to sections are written as `index.md` within subfolders and are assigned no title and a negative weight to place them right after the section headline.

Documentation snippets are located for organizational purposes within `chapter/section` subfolder but association to a certain section is done via the `category` key in YAML prelude.

Local changes can be tested via:

```sh
sudo gem install bundler
bundle
jekyll serve
```
Webserver runs on http://0.0.0.0:4000/Tidal/

Theme is made with [Bootstrap 3](http://getbootstrap.com) based on the [Lumen Theme from bootswatch](http://bootswatch.com/lumen/) and can be further customized by changing:

- `_sass/tidal/_variables.scss`
- `css/tidal.scss`

Code highlighting is done via pygments using [solarized-light theme](https://gist.github.com/scotu/1272660)

Current state can be seen in my [Tidal fork](http://lennart.github.io/Tidal/)