Refer to community in landing page

[xlxs4]

Leaving this here so people can collaborate on the text. Will then need some styling

[KeithWM]

Should we also include an improvement of the Community page in this PR? Because while this addition is definitely an improvement, I think the Community page does little to help users, instead overwhelming them with many different channels named in a rather inconsistent fashion.

The current design contains:

• Github
• Questions?
  • Discourse
  • SO + SO en Espanol
• Chat
  • Slack
  • Humans of Julia Discord
• Youtube
• Twitter (now officially "X")
• Forem

And under a link to "Other channels":

• LinkedIn
• Facebook
• Pinterest
• Instagram

I would argue:

1. GitHub should not be on that list, it is not a community channel
2. There should be an official choice between Discourse and SO
3. There should be an official choice between Slack and Discord
4. The recommended choice should be on the first page, the other on "Other channels" page.
5. YouTube should stay as a nice welcoming place
6. Twitter and Forem are not as relevant and should be on the "Other channels" page.

So my suggestion would be

• SO [optinally also SO en Espanol]
• Slack
• Youtube

And under the link to "Other channels":

• Discourse
• Humans of Julia Discord
• Twitter (now officially "X")
• Forem
• LinkedIn
• Facebook
• Pinterest
• Instagram