Refs #10563 Add interfaces category to offline documentation
Refs #10563 Add initial ISIS Reflectometry interface documentation
Refs #10563 Add "help" action to Reflectometry UI
Refs #10563 Add python bindings for createSubWindow

We need this to generate documentation screenshots of c++ custom
interfaces
Refs #10563 Generate screenshots for custom interface documentation
Refs #10563 Add troubleshooting instructions to Refl UI documentation
Refs #10563 Christen the new Refl UI
Refs #10563 Insert TOC manually
Refs #10563 Add "widget" option to interface directive

This option allows you to specify a widget's name to screenshot just
that widget.
Refs #10563 Support custom alignment
Refs #10563 Use widget screenshots in Refl UI docs
Refs #10563 Add example workflow to refl ui docs
Merge remote-tracking branch 'origin/feature/10563_new_refl_ui_offline_documentation'