migrate Markdown files to AsciiDoc, AsciiDoc config

- migrate several pages from Markdown to AsciiDoc
- reset AsciiDoc imagesdir attribute to blank
- fix AsciiDoc syntax on source code page
- add polaroid style for images, use on team page
Merge pull request #1 from mojavelinux/asciidoc-updates

migrate Markdown files to AsciiDoc, AsciiDoc config