README updates with tips, FYIs, and org owner SOPs

[BigLep]

Summary

I'm adding some additional docs based on working in this repo the last month. I also started documenting SOPs for org owners.

DRI: myself

Reviewer's Checklist

• [ ] It is clear where the request is coming from (if unsure, ask)
• [ ] All the automated checks passed
• [ ] The YAML changes reflect the summary of the request
• [ ] The Terraform plan posted as a comment reflects the summary of the request

[github-actions[bot]]

The following access changes will be introduced as a result of applying the plan:

Access Changes

``` There will be no access changes ```

[github-actions[bot]]

Before merge, verify that all the following plans are correct. They will be applied as-is after the merge.

Terraform plans

filecoin-project

``` No changes. Your infrastructure matches the configuration. Terraform has compared your real infrastructure against your configuration and found no differences, so no changes are needed. ```