docs: update outdated arc.network domain references to arc.io

[mrnetwork0001]

Hi team! I noticed that Arc has migrated its domain to arc.io, but there were still 38 references to the old arc.network domain across the documentation and README. I've gone ahead and updated all of them to point to the correct new domain.

[nenadmilosevic95]

Service endpoint domains haven't migrated.

Thanks for the contribution! The www.arc.io and docs.arc.io changes look correct and good to merge.

However, the service endpoint subdomains introduced by this PR don't resolve yet:

https://rpc.quicknode.testnet.arc.io/   → DNS FAIL (host not found)
https://rpc.drpc.testnet.arc.io/        → DNS FAIL (host not found)
https://rpc.blockdaemon.testnet.arc.io/ → DNS FAIL (host not found)
https://snapshots.arc.io/               → DNS FAIL (host not found)

The corresponding arc.network endpoints are still live. We'd suggest reverting the service endpoint changes and keeping only the www/docs updates in this PR.

[mrnetwork0001]

Service endpoint domains haven't migrated.

Thanks for the contribution! The www.arc.io and docs.arc.io changes look correct and good to merge.

However, the service endpoint subdomains introduced by this PR don't resolve yet:

https://rpc.quicknode.testnet.arc.io/   → DNS FAIL (host not found)
https://rpc.drpc.testnet.arc.io/        → DNS FAIL (host not found)
https://rpc.blockdaemon.testnet.arc.io/ → DNS FAIL (host not found)
https://snapshots.arc.io/               → DNS FAIL (host not found)

The corresponding arc.network endpoints are still live. We'd suggest reverting the service endpoint changes and keeping only the www/docs updates in this PR.

Thanks for the feedback!
I have reverted all the service endpoint subdomains (RPCs and snapshots) back to arc.network since they do not resolve yet, while keeping the main website and documentation links updated to arc.io. The PR has been updated with these changes.