Use markdown check box for Tasklist

[jsixface]

When creating a task from the toolbar in the bottom creates a task list with check-able list in the app. When that note is synchronized with a Nextcloud instance, it converts it to a plain text list. Checked / Unchecked status is not updated in that note.

Feature Request:

Convert that task list to a markdown document with check boxes. This will preserve the state of the list across devices when using a sync service like Nextcloud.

[jsixface]

Duplicate of #146