contact everyone about the introduction of auth blocking all requests without auth

[hannahhoward]

No description provided.

[gruns]

TODOS:

• contact metaplex, our only official user/customer, and tell them to update their browser client to use the new version which adds an auth header
• make announcements in both #filecoin-saturn and #fil-saturn-announcements to give users a heads up that an auth token will be required for network access going forward. link them to the portal
• add to docs.saturn.tech how to add auth to HTTP requests for CLI tools -- curl, wget, etc. this documentation is both for us, internal saturn team usage, and other external users who were using, exploring, and playing with saturn before and now need an auth token to continue

[reidlw]

I've drafted the comms and sent to Saturn leads to get other eyes on it before it gets sent

cc @mroth @gruns @prodalex