Dashboards

• Charging Curves: Unified ranges in the graphs to be able to compare better.
• Charging Curves: Added maximum and minimum power value of the charger.

Other changes

• New system to download the latest stable version of the dashboards and install them
• Updated readme file with instructions for the new installation system
• Updated screenshots

Full Changelog: https://github.com/CarlosCuezva/dashboards-Grafana-Teslamate/compare/v1.12.0...v1.13.0