Docs: Update docs after peer review

[RHammond2]

This PR fixes a myriad of issues found in a review of the updated documentation. These fixes include:

• updating the export system comparison to use the total substation cost, a longer cable distance, and adds a new plot showing when more cables and substations are required.
• updates confusing text descriptions and adds further clarification where needed.
• adds additional installation timing metrics to the available outputs demonstration
• removes deprecated or nonexistent functionality like substructure storage limits for fixed bottom installations and the ability to override substructure dimensions.

The overnight capex has also been updated to reflect the definition provided in the ATB.