Update getting started docs (#3871)
Update getting started docs (#3871)

* Remove confusing quickstart section

* Add note about verifying ports are available

* Add some clarifications around serve, initdb

* Be more imperative

* Make links clickable

pypa/warehouse,dstufft/warehouse,dstufft/warehouse,pypa/warehouse,pypa/warehouse,dstufft/warehouse,dstufft/warehouse,pypa/warehouse