Completed tutorial updates (mid_load equations fixed and added a figure and clarifications to other points).
Copied the node investment parameters to unit investment parameters.
Added how to page and it's first example how to build a hydro reservoir.
The example database added to a new folder 'how to example databases'.
Completed tutorial updates (mid_load equations fixed and added a figure and clarifications to other points). Copied the node investment parameters to unit investment parameters. Added how to page and it's first example how to build a hydro reservoir. The example database added to a new folder 'how to example databases'.