NXBOOK-757 removed content about disabling security and updated screenshot
NXBOOK-757 documented releaseAfterClose flag from NEXUS-5906
NXBOOK-757 minor corrections regarding not using Plexus for plugin dev, more needs to be done on this
fixed images to reflect the desired setting as documented in the text
Merge branch 'master' of github.com:sonatype/nexus-book