How to edit documents with Documenter

Documenter is the Glamorous Toolkit engine with which we can create live narratives directly in the development environment.
Presently, Documenter is supported by the user interface in two ways:
- in the comments of Pharo classes
- when editing .pillar files
When browsing a class comment, you can use Pillar markup syntax and through it embed various artifacts.
Similarly, inspecting any .pillar file will offer a Document view through which you can edit and render the document live:
'my.pillar' asFileReference 
    writeStreamDo: [:s |
    	s nextPutAll: '!My document' ];
And, of course, a document can also be created programmatically and edited in the Inspector, too:
GtDocumenter forText: '!My document'