Updated docs on how AWS credentials are resolved

Document behavior of AWS {access,secret}_key in relation to credentia…

Update setup documentation to cover issue #1117

Fixes #2478

Added a static version of this so we can partial it into place in the layout. This prevents it from being reformatted.

- Reformat .html / .erb files
- Remove extra </div> in index.html.erb
- Add htmlbeautifier gem
- Add middleman-breadcrumbs
- Add make format (calls htmlbeautifier)

website: remove packer push var interpolation

This removes a message that is no longer accurate and fixed in https://github.com/mitchellh/packer/issues/1861

In issue #1117, the packer binary can sometimes conflict with the packer binary supplied with cracklib. This documentation update covers this and provides workarounds for affected users.

Document behavior of AWS {access,secret}_key in relation to credentials file and profile lookup via AWS_PROFILE

Fixes #2474:  Replace use of 'int' and 'uint' in website docs with 'integer' and wrap long lines

Add description of force option for docker-tag

Make manifest_file work as either file.pp or a directory