docs: clarify startup instructions

7 jobs for postgres in 6 minutes and 39 seconds (queued for 2 seconds)
Status Name Job ID Coverage
  Build
passed build #13911

00:01:48

 
  Test
passed lint #13914

00:00:13

passed test:chrome #13912

00:03:43

passed test:firefox #13913

00:01:09

 
  Review
passed review #13915

00:00:42

passed stop_review #13916
manual

00:00:23

 
  Demo
manual demo #13917
allowed to fail manual