tests/test-debugindexdot.out

doc: use reST note directive

The 'NOTE: bla bla' syntax was for asciidoc and is still present in a
couple of docstrings. The docstrings will be converted to reST format
when minirst knows how to handle it.

created new head
digraph G {
	-1 -> 0
	0 -> 1
	0 -> 2
	2 -> 3
	1 -> 3
}