[BUGFIX] Fixing unwanted indentation in Administrator + User manuals
[TASK] Opening Highlighter/Configuration for class extension
[DOC] Improving 2.0 to 2.1 upgrade / installation information (Screenshot)

This change introduces a screenshot in order to show the Administrator / Integrator
which static TypoScript templates needs to be used and ordered to use the
DynamicPageAssets feature.
[BUGFIX] Setting TypoScript defaults (gutter, line highlighting) in Flexform DO