Read only-mode (and fragment rendering)

[streamich]

Fragments

• [ ] For plugins ability to render "fragment" (instead of "peritext")
• [ ] Add ability to render selected fragment in read-only mode
• [ ] Show/render selected fragment

Read-only fragments

• [ ] Read-only mode, can only read text not edit.
• [ ] Make links clickable (unlike in edit mode, on link click it opens a popup).
• [ ] Context flag for all renderers.
• [ ] Enforce read-only on json-joy document level.
  • [ ] Any mutations are disabled.
• [ ] CSS changes
  • [ ] Kerning re-enabled
  • [ ] Ligatures enabled
• [ ] HTML changes
  • [ ] Disable [contenteditable]
  • [ ] Disable cursors
  • [ ] Disable some DOM events
• [ ] Chrome UI changes
  • [ ] Surrounding UI
  • [ ] Toolbars