GS6.0 Chapter 4 Updates

I have uploaded my chapter 4  draft to ODF Authors and updated the task

In the sections "Formatting Paragraphs" and "Formatting Characters" I
have stressed the difference between direct manual formatting using the
formatting toolbar and formatting using styles.

Added a new section about the "Custom Watermark" feature.

There is no existing detailed explanation of the full context menu
options, so I propose we continue to reference these options as and when

Chapter 4 does not make any reference to the Web Wizard, that is a
revision for chapter 12.

There is no existing reference to Outline Numbering in this chapter, so
there is no requirement to change anything to Chapter Numbering.