Renamed interface_navigate.rst to the i_ version, linked to the renamed i_export. Changed the text at the start of the export docs to list the available exports in this release. Added text and image of the exports list, haven't covered deleting. Commit to see if image needs resizing for rtd. Refs #104.
Added in the dimensions of the image, contrary to the RTD docs recommending no dimensions due to the responsive layout. Without the dims, the image resizes with no link to the full size version. With dims, the image can be clicked on to get the full version. Refs #104.