Wrong image in Fuel user guide

Re-captured screenshots.
Changed requirements to match with Fuel 3.2.1
Corrected user guide, added info about Windows support.
Corrected VM info.

Change-Id: I49e04c9c30b779b796f95230cc3c5af6456c3546
Closes-Bug: https://mirantis.jira.com/browse/PRD-2500
Merge "Wrong image in Fuel user guide"