Convert axhline, axvline, and vertical/horizontal axline to layout shapes - #5719

Convert axhline, axvline, and vertical/horizontal axline to layout shapes#5719

camdecoster merged 16 commits into

plotly:mainplotly/plotly.py:mainfrom

robertoffmoura:rm/support-axhlinerobertoffmoura/plotly.py:rm/support-axhlineCopy head branch name to clipboard