Update start building section and chain configs

[eshaben]

Description

This PR includes the following changes:

• It removes get started with X pages. These pages had a lot of duplicate content that you can find in the reference section
• It updates the supported networks pages and separates the networks by environment and switches to a table format to make it easier to scan. The icons were nice, but I feel like it's more concise this way. If you have alternative suggestions or ideas, let me know 🙂
• It switches the testnet faucets page to split the testnets up by environment and show the faucet data in tables
• It also updates the reference section pages to include the latest chain data. Removing any rows without data so these tables can be a bit cleaner

Checklist

• Required - I have added a label to this PR 🏷️
• If pages have been moved, I have created redirects in the wormhole-mkdocs repo
  • Redirects are in this mkdocs PR: Update scripts papermoonio/wormhole-mkdocs#104

[martin0995]

LGTM! I left one small comment on this PR related to the Supported Networks and Testnet Faucets links.

[ilariae]

lgtm!