Revise TOC on index page to show 0.0 sections

[benschwarz]

Right now we're showing hard numbered sections:

1 2 3 4 5 etc etc.

We should open up the selector to show: 1 1.2

but not

1 1.2 1.2.3

[benschwarz]

A difficult change to modify the index.html table of contents (Closed by 4081dcc0011df251fb7fa036e70af2b18a6b8fb6)

• Second level items that are on the same page as the parent are removed
• Second level items that aren't on the same page as the parent are shown