chore: remove _isStarted as it's no longer used
chore: remove _isStarted as it's no longer used

_isStarted is an outdated property and shouldn't exist
in the code anymore. The state machine handles start
logic and the isStarted computed property pulls from there.
The code comments around dht and pubsub are also no
longer valid, so they were deleted.

diasdavid/node-libp2p,diasdavid/js-libp2p