Docs to pdf

[charlesreid1]

Add script+instructions for creating a final PDF from the documentation using mkdocs-pandoc.

Also adds documentation to the binary file dahak_docs.pdf

Merge Checklist

• [x] Typos are a sign of poorly maintained code. Has this request been checked with a spell checker? yesssssssss
• [x] ~Tutorials should be universally reproducible. If this request modifies a tutorial, does it assume we're starting from a blank Ubuntu 16.04 (Xenial Xerus) image?~ n/a
• [x] Large diffs to binary or data files can artificially inflate the size of the repository. Are there large diffs to binary or data files, and are these changes necessary? yes, only adding the final version of documentation in PDF format.

[charlesreid1]

Link to the nice PDF version of the documentation: https://github.com/dahak-metagenomics/dahak/raw/df948251056dd61cebf66d9dbe9c1277c30b60a0/dahak_docs.pdf

[brooksph]

Nice! It seems as though pandocs does not automatically wrap the text as some of the code blocks are outside of the margins (e.g. pg 5, 19, etc.). An alternative to manually inserting line breaks is not readily apparent. Any thoughts @charlesreid1?

[charlesreid1]

Hmm... most are URLs so we can turn those into TinyURLs. The rest are walkthru/docker commands that can be broken up and line-wrapped with \