Add figure cross references

[eldobbins]

Figure cross references are described at https://quarto.org/docs/authoring/cross-references.html. This method was followed within method.qmd and it worked great

For Observable figures specifically see https://quarto.org/docs/interactive/ojs/ojs-cells.html#cell-figures. This method was attempted for capacity,qmd. For figures 2 and 3, it worked great. But for figure 1, it thinks there is a subplot with the first one (a) being empty and the second one (b) containing the plot. Don't know what is going on there.

• [x] capacity - fix figure 1 subplots that says "b"
• [x] generation
• [x] prices
• [x] consumption - figure 3 is sub-plotting too. it says "c"
• [x] methods

[eldobbins]

Subplot issue was because of extra code before the Plot section. Move that code into a separate {ojs} block and the subplots go away.