(maint) Add docker command for Windows to README

[alexaveldanez]

Description Of Changes

Adds the docker command for Windows.

Motivation and Context

This command is needed to build the docs site with docker on Windows.

Testing

• I have previewed these changes using the Docker Container or another method before submitting this pull request.

Change Types Made

• Minor documentation fix (typos etc.).
• Major documentation change (refactoring, reformatting or adding documentation to existing page).
• New documentation page added.
• The change I have made should have a video added, and I have raised an issue for this.
  • Issue #

Change Checklist

• Requires a change to menu structure (top or left-hand side)/
• Menu structure has been updated
• Images added to the img repository?
  • PR -

Related Issue

Fixes #

[st3phhays]

LGTM!