feat: add format quality factor
style: uniform code style and untabify
feat: paramterize number of y-grid, revert to 8
feat: add marker tracking
feat: improve frequency accuracy
feat: draw marker value in white
Merge branch 'master' of github.com:ttrftech/NanoVNA
feat: add marker operation groupdelay->edelay
fix: make touch cal default suitable for 2.8 panel
doc: add guide on clearconfig