Lists

[Cheba]

I've checked a doc on markdown and found a recommendation on list
numbering.

> If you do use lazy list numbering, however, you should still start the list with the number 1. At some point in the future, Markdown may support starting ordered lists at an arbitrary number.

Currently toc starts from 0. I think we should follow the
recommendation even if it's just a recommendation and at the present
time doesn't make any difference.

Also first level list uses sequential numbering and second level lists
use lazy numbering.

Also some second level lists are indented with tabs and some - with
two spaces. Probably, we have to be more consistent.

[Dale Campbell]

Sounds good to me.

Regarding the indentations, I think we should stick to spaces instead
of tab characters. That would make things a bit more consistent, IMO.

[zhonghai zuo]

Spaces make more sense...

--Z

[Matt Aimonetti]

I'm in agreement with both recommendations, can someone edit the guidelines on the group page please?

- Matt