WIP user guide
move user_guide to docs dir
correct links and formatting description.
add start of info on permissions
change user guide to rst, prepartion for sphinx
conversion of md to rst
convert md backtick to rst backtick
update user-guide.rst, minor corrections
add user-guide to autogenerated sphinx docs
WIP
add details of group permissions
clean up user-guide
further cleanup of user guide, pre merge
updates to permission info on User Guide
Merge pull request #88 from girder/start_user_guide

Start user guide