update README:
update README:

- add modules to TOC
- add info about version cdn URL
- generalize path to `custom-plotly.js`
- add info about cwise transform

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