Zlatko Knezevic 09b6be5990 Cleaning up the documentation folder (#5928 )

* Cleaning up the documentation folder

This change cleans up the documentation folder in the CLI repo. The
changes are the following:

* Delete old content that is invalid moving forward.
* Move cli-installation-scenarios to the `specs` sub-folder.
* Add a sub-folder for documentation that deals with working with the repo
* Add a general sub-folder
* Finally, change the README.md to reflect this.

Also, this change adds a document that covers CLI UX guidelines for
authors of new commands.

* Firt round of PR feedback changes

2017-03-09 17:09:59 -08:00