properly delete nested attributes, update doc `crawl`
properly delete nested attributes, update doc `crawl`

aburato/plotly.js,asolagmbh/plotly.js,etpinard/plotly.js,etpinard/plotly.js,etpinard/plotly.js,plotly/plotly.js,aburato/plotly.js,plotly/plotly.js,asolagmbh/plotly.js,plotly/plotly.js,plotly/plotly.js,asolagmbh/plotly.js