Setting up AutoCNet to interact with RTDs (#583)

* adding RTD files

* dont build NBs and export ISISROOT to environment

* adding dummy ISISDATA env variable for kalasiris

* adding nbsphinx to environment and incorperating very bad work around to kalasiris import requirements

* addressing warnings

* adding workshops index.rst

* simplifying docs environment requirements and mocking models, reverting junky kalasiris workaround