docs: update docker page with updated flow

[jcstein]

fix up docker page

1. quick start - this should be the first step
2. persistent storage
   1. Don't need init, remove this step
   2. this guide should show you how to (a) make store location (b) then run with that store location
3. 3rd option, "use light node with rollup"
   1. move the advice for ports to the bottom where you have a
4. Nice-to-have: use names to name the container to make it easier to interact with

cc @MSevey for vis and for anything I missed

[jcstein]

to be done after celestiaorg/celestia-node#3808 is live

[MSevey]

Another thought for the quick start section might to also just hardcode some more values and make it clear that it is for starting a light node to sample.

Then the only decision is which network to target. And with that even hardcoding the RPC endpoint for them. I honestly mess up that endpoint every time.

Although I know you are also trying to improve the rpc endpoint table documentation page so that might help. But either way I think the quick start shouldn't make someone leave the page for any information.

[jcstein]

Notes from slack discussion:

When I was doing some testing with the docker images, it appears that the ENV VARs are used to set the config.toml file during the celestia init command that the dockerfile entrypoint script calls.
While the flags are for the celestia start command.
--
I know many people manually set their config files, so they wouldn’t need to set the ENV VARs in that instance I’m pretty sure.

[jcstein]

From discord:

It exposes gateway port, however, documentation says gateway is deprecated