Operating System section -> Create raw image with Packer

[thebsdbox]

In the Deploying Operating Systems section of the docs, add in a document that details the basic usage of Packer to create a raw image (can be compressed with gz afterwards). Followed by the basic workflow required to deploy this image to a target machine.

[DailyAlice]

Just a note - I went ahead and merged the PR that contained the bulk of the content #100.

I was going to put out a PR to add it to mkdocs.yml but got kinda involved in editing it, so didn't get it done. I do have a branch going though, and I should be able to get it done tomorrow. (Sorry!)

[Cbkhare]

#100 is merged