restack: Be topological and update docs

[jerry-skydio]

Restack will now topologically reorder your relative
graph to be linear again. Update docs to reflect this
and the conflict handling.

[jerry-skydio]

Reviews in this chain:
└#165 restack: Be topological and update docs

[jerry-skydio]

#	head	base	diff	date	summary
0	b9b66c58	df295937	diff	Mar 13 11:38 AM	2 files changed, 8 insertions(+), 8 deletions(-)
1	5781133e	2d8cc8e9	rebase	Mar 13 12:01 PM	0 files changed
2	659f9402	65cc1b54	rebase	Mar 13 12:03 PM	0 files changed
3	3a4094b3	f3f012a2	diff	Mar 13 13:40 PM	2 files changed, 1 insertion(+), 4 deletions(-)
4	2ec8df46	79d040b3	diff	Mar 13 13:50 PM	1 file changed, 7 insertions(+), 8 deletions(-)
5	176df8ee	9a5a6e35	rebase	Mar 13 14:02 PM	0 files changed
6	5d873133	4c4b4572	diff	Mar 13 14:03 PM	0 files changed

[aaron-skydio]

Nice