Document Getting data into the tale

[craig-willis]

Update user guide to include description of how to get data into the tale. Scenario: user has data on their laptop and wants to add it to a Tale. Will include upload and mounting webdav

[ThomasThelen]

Documentation for registering data from Globus and DataONE has been documented at the following
http://wholetale.readthedocs.io/users_guide/manage.html

Adding registered data to a tale has been documented under the Adding Data section at
http://wholetale.readthedocs.io/users_guide/compose.html

Finding and selecting data can be found at
http://wholetale.readthedocs.io/users_guide/run.html

Webdav integration has not been included.