* add lower level configuring mixer document in tasks
* review comments
* review comments, and variables
* move to concepts, and links
* format bash and output per style guide
The directory structure of the input web site now controls directory the layout of the
doc hierarchy. This simplifies authoring documents and enriches the UI we generate.
This also fixes the broken link problem with the GitHub staging sites. Most links work
now.
Our sitemap.xml now contains all that it should, and excludes stuff that it shouldn't contain.