Move general usage information into a file.

[bethac07]

Wikis don't get cloned with template repos, but files do. If there is any general-purpose use instructions we want to be included in child repos, we should make them into files.

[ErinWeisbart]

Find with #4 by the creation of documentation/DS-documentation
Documentation will be included as part of template usage and includes explicit instruction for customizing both Distributed-Something and the DS-documentation.