Change mention of conda (was: change conda to miniforge)

[eteq]

This is really just a companion to astropy/astropy#16555 to synchronize what's on the web site with whatever that settles on. Please have discussion about what we should actually recommend in astropy/astropy#16555 so that we don't spread it around multiple threads.

Rendered doc: https://output.circle-artifacts.com/output/job/fc974b2f-31be-45e0-a824-116fb2da9647/artifacts/0/html/index.html

[bsipocz]

I don't see any usage of miniforge install over there.

~That is a very very unfortunate outcome. Switching from conda to miniforge was a clear recommendation coming out of the NF summit. Those PRs ended up in the usual bikeshedding of pip vs conda for experienced developers, and neither should those POVs drive the end-user recommendations, and IMO more modern tools should be taken into account (I'm thinking of pixi) even if core developers stay on using their own preferences due to muscle memory).~

~So, I'm with @eteq here and strongly suggest ditching conda in favour of miniforge (even though my own bikeshed is pip-coloured).~

Never mind my comment, the install page indeed ditched miniconda for miniforge, so the actual conda command is ru from the right place. And it's just an unfortunate side effect that the commands look the same but the configs are different.

So, my comment for this section would be to fully get rid of it; and only point to the install guide in the docs as there isn't enough space to go into the nuances between conda install and conda install...

[pllim]

I took the liberty to push a follow-up commit here in response to review from @bsipocz . Hope you don't mind, @eteq !

Does it look less confusing now?

[pllim]

Thanks for the review, @taldcroft ! I accepted all your suggestions.

[pllim]

@taldcroft , what do you think? Good to merge?

[pllim]

@bsipocz , conda install instruction is gone. Can you please re-review as well. Thanks!