Changes include "guide book(s)" to "guide(s)" in par. 3 and 4 (lines 8, 10).

In second paragraph remove space between "overview] (https" to read "overview](https:" so that URL does not appear adjacent to "basic overview".

Identify two environments:  Docker for Windows / Mac / Linux and Legacy
OS (Windows 7, 8.1, 10 Home Premium).  Provide docker run commeands for
each environment.

Close #184

Close #86

This way the docker image shows the repository that was used to generate
the image and people can go to that repo to look at the Dockerfile used.

Update docs home page URL

I found that I needed this package locally or I got this error: `ImportError: Failed loading extension 'pymdownx.superfences' from 'pymdownx.superfences', 'markdown.extensions.pymdownx.superfences' or 'mdx_pymdownx.superfences'` when trying to build

Closes #90