docs: document gcp backup

[marcoieni]

Related to #122
This PR documents the GCP backup I will implement (the document assumes that the feature is already implemented).

This document is taken from the hackmd document shared in zulip.
I slightly edited it to:

• remove the parts that don't fit for docs, such as the execution plan and the two remaining unresolved questions and pricing calculation. I copied the plan and questions in Back up Rust releases and crates #122 (comment).
• address some comments (e.g. the region is now in europe)
• adapt the style (from RFC to docs).

[jdno]

This is a great starting point and I'm happy to see that we're slowly adding documentation for our services! 🤩

[jdno]

I think GCP is an implementation detail and would therefore rename this piece of our infrastructure (i.e. the document). Internally, we've talked about this in terms of "backup of critical (Rust) assets". How about we use a similar name for this "service"?

[marcoieni]

what do you think of aebc9e6 ?

[jdno]

Nit: I'd either call the the "(I|i)nfrastructure team" (without a strong preference for capitalization) or the "infra-team", with a preference for the first. We're optimizing for readability here, and imo abbreviations make it more difficult to read long documents. But that's totally a personal opinion of mine...

[marcoieni]

82e3135 👍

[jdno]

Nit (another personal opinion): When talking about Terraform, the product, we should capitalize its name. When talking about terraform, the CLI, we should wrap it in a code "block". (This goes for all product names, e.g. CloudFront further down.)

[marcoieni]

1000b25 👍

[jdno]

A question that I had while reading the document is what its purpose and target audience are. Using the Diataxis framework as a reference, I feel like the current document mixes a project plan, explanations, points that we should probably expand into how-to guides, and tasks.

Thinking long-term, I think the README.md should probably give a high-level overview of the service, what it tries to achieve, and in only a few sentences how it does that. And then we link to individual documents that provide more information and how-to guides for specific tasks. I think that'll provide a more scalable and easier-to-manage structure, even though the initial complexity will be higher.

What do you think?

[marcoieni]

The original format of the doc reflected the rust rfc process, but I guess that's used for discussions, while here we should adopt the diataxis style. 👍

I extracted FAQ and maintenance in separate docs.

Let me know if you think readme is still longer then it should be.