Documentation and charge curve improvements

What's Changed

• Predbat now has input_number.predbat_battery_rate_max_scaling_discharge which is separate from input_number.predbat_battery_rate_max_scaling (which is now just for charging). This allows the user to tune down the modelled charge rate without changing the discharge rate. Calibration of the charge rate can be found in the charge curve calculation feature
• Added discharge curve calculation feature (GE inverters seem to flat)
• Lots of documentation improvements and code cleanup

---

• Improve charge curve, and add discharge curve calculations by @springfall2008 in #690
• Fix unit display on input_number by @springfall2008 in #691
• Documentation updates by @gcoan in #692
• Update apps.yaml by @springfall2008 in #694
• Code cleanup by @marksie1988 in #656

New Contributors

• @marksie1988 made their first contribution in #656

Full Changelog: v7.15.10...v7.5.11