include a note about versions

[chriddyp]

see discussion in #161

[chriddyp]

[jbrandes]

This still isn't working for me. Dash core components still doesn't load even with those instructions.

import dash_html_compontents as html
ModuleNotFoundError: No module named 'dash_html_compontents'

[alexcjohnson]

@jbrandes this PR is pretty old, installation is much simpler now than it was last September. Per https://dash.plot.ly/installation, all you really need to do is pip install --upgrade dash (for the latest version) pip install dash==1.0.0 (if you need a specific version >=0.37.0) and you will get the proper versions of dash_core_components, dash_html_components (note the spelling) and dash_table