Merge branch 'jn/notes-doc' into maint

Merge branch 'jn/notes-doc' into maint

* jn/notes-doc:
  Documentation/notes: nitpicks
  Documentation/notes: clean up description of rewriting configuration
  Documentation/notes: simplify treatment of default display refs
  Documentation/log: add a CONFIGURATION section
  Documentation/notes: simplify treatment of default notes ref
  Documentation/notes: add configuration section
  Documentation/notes: describe content of notes blobs
  Documentation/notes: document format of notes trees