Spike: explore nested items

[jotaen]

One of the most wanted features in the [x]it! file format is nested sub-items, so e.g.:

[ ] Big project
    [ ] Task 1
    [ ] Task 2
        [ ] Sub-Task of Task 2

I’ve already tried to implement support for this functionality in the Sublime plugin, but without success. Problems include the following:

[x] Big project
        [ ] It shouldn’t be possible to “skip” a level
    [ ] If parent is checked, also mark all subitems as checked, regardless of their status
    It shouldn’t be possible to continue the description of “Big project” here

I wasn’t able to make that happen, but if anyone else would be willing to give this a shot, feel free to create an explorative spike PR.

Regarding the discussion itself, I think it’s important to have a least one working implementation to play around with, in order to assess the technical difficulties better, and in order to get a better feeling for the behaviour and corner cases of nesting.