Update README.md

Updated .gitignore, added first steps of gain/offset tracking and correction

Moved hardware .gitignore to hardware folder.

Updated .gitignore file

Merge pull request #12 from ekatynski/promo_image Update README.md

Update README.md Added photo of the calibrator device to the README

Merge pull request #11 from ekatynski/promo_image Added photo of the device for display in the README

Added photo of the device for display in the README

Merge pull request #10 from ekatynski/ekatynski-patch-1 Update note.md

Update note.md Updated disclaimer regarding harness diagram for L01Z board.