Editor refresh.

- Fixed internal links (#35).

Version bump.

Editor upstream changes.

- Collapsible headers
- Better checkboxes
- Don't replace text when using slash command.

Upstream changes. Updated README.

Added support for tweet embeds.

Support links inside the same document.

Updated the editor from upstream. Fixes #21 and #14.

Fixes #20.

After updating the editor to the latest version the list items were not wrapping correctly, probably caused by a third party library change.

Release 0.12.0.

Update to the latest editor.

Be always compatible with One Dark Darker theme.