Add documentation about "watch" commands next to --no-sort (#634)
Add documentation about "watch" commands next to --no-sort (#634)

I ran into an issue where `lerna run build:watch` ("build:watch" being a
babel command with the `--watch` flag) would only run for one package
(called "core"). It turns out to be caused by lerna running commands in
a topologically sorted order, executing packages that others depend on
first before moving on.

The nature of "watch" commands is usually to never end. In my case that
meant that lerna was waiting indefinitely for the "core" package command
to finish.

By reading the documentation I came across the `--no-sort` flag, which
helped resolve my issue. It wasn't super clear in the README that this
flag would help out with my problem, so I decided to add a little bit
about "watch" commands right next to it.

Relevant discussion:
https://github.com/lerna/lerna/issues/449#issuecomment-283463490
onigoetz/lerna-hg,evocateur/lerna,lerna/lerna,sebmck/lerna,FaHeymann/lerna,evocateur/lerna,lerna/lerna,kittens/lerna,treshugart/lerna,lerna/lerna,tbayaa/lerna