[docs] Add link for launching ray manually in quickstart (#15384)
[docs] Add link for launching ray manually in quickstart (#15384)

Co-authored-by: Richard Liaw <3230d85c7494674e1ab9b2b5f7d3b4d6790b2a83@berkeley.edu>
ray-project/ray,pcmoritz/ray-1,pcmoritz/ray-1,ray-project/ray,pcmoritz/ray-1,ray-project/ray,ray-project/ray,ray-project/ray,pcmoritz/ray-1,ray-project/ray,pcmoritz/ray-1,ray-project/ray,pcmoritz/ray-1,pcmoritz/ray-1,ray-project/ray,pcmoritz/ray-1