feat: add mincharge sensor

[firstof9]

• change rate icons
• related to #45
• bump library version

[codecov-commenter]

Codecov Report

Merging #47 (6b41183) into dev (8efc280) will increase coverage by 2.66%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##              dev      #47      +/-   ##
==========================================
+ Coverage   92.65%   95.31%   +2.66%     
==========================================
  Files           5        5              
  Lines         354      363       +9     
==========================================
+ Hits          328      346      +18     
+ Misses         26       17       -9     

Impacted Files	Coverage Δ
custom_components/openei/const.py	100.00% <ø> (ø)
custom_components/openei/__init__.py	89.71% <100.00%> (+5.25%)	:arrow_up:
custom_components/openei/config_flow.py	96.27% <100.00%> (+2.48%)	:arrow_up:
custom_components/openei/sensor.py	100.00% <100.00%> (ø)

[github-actions[bot]]

🎉 HACS repository validator action summary 🎉 ✅ The repository is not archived ✅ manifest.json file exist ✅ All required keys are present in manifest.json ✅ hacs.json has the 'name' key set ✅ The repository has a description ✅ openei is added to https://github.com/home-assistant/brands NICE! ✅ The repository has topics ✅ The repository has issues enabled ✅ This day ends with an 'y' (Saturday) ✅ info.md exists ✅ Requirements validation ✅ Python wheels ✅ HACS load check