content instructions
- Adding documentation on using the ‘Disallow page types’ feature.
- Fix links
- Re-word documentation to clarify important points.
- Add new content from Sig, tidy up existing content.
- MINOR: Formatting update & draw attention to links at the bottom.
* Updated graphics
* Updated information around global dropdown
* Added Information about supporting subsites in modeladmins
* Changed 'working.md' to 'working_with.md', for clearer menu naming