Power Plants

[Indy2222]

• There is a new building type called "Power Plant".
• It generates energy at a constant rate (a constant in the code).
• It consumes energy like any other building (see Simple Batteries #473).
• The generated energy goes into its battery until maximum battery charge is reached.

Note that energy distribution is not implemented as part of this issue.

[github-actions]

There is no activity on the issue for some time.