Doc update needed for release of 5.5.5:

• CONTEDIT-101
• CONTEDIT-74

For a full list of dev tickets tackled since the last doc update, see: https://jira.magnolia-cms.com/issues/?filter=16862

See recording of demo from PD team meeting 29/05 for info on the two tickets listed above: afp://fileserver.magnolia-cms.com/All/Product Development/Knowledge Transfer/2017/2017-05-29 11.13 Product Team Meeting.mp4

• Update doc about the "outline" to describe multiple collapsible composite fields.
• Add the "Link to Magnolia item" option in block chooser bar to the Stories app page.
• To configure the apps you can link to, in the content definition add:
  linkableApps: + apps
  NB: Plugin only available in the content-editor (not in normal ck editor YET).