chore: first pass at docs for the delivery firehose

[travis]

I think these need more work, but want to see how this lands.

[seed-deploy[bot]]

View stack outputs

- **pr321-w3infra-BillingDbStack** Name | Value -- | -- customerTableName | pr321-w3infra-customer spaceDiffTableName | pr321-w3infra-space-diff spaceSnapshotTableName | pr321-w3infra-space-snapshot usageTable | pr321-w3infra-usage - **pr321-w3infra-BillingStack** Name | Value -- | -- ApiEndpoint | https://rjv6sq6j9l.execute-api.us-east-2.amazonaws.com billingCronHandlerURL | https://xbuumnprmpnkvyr67uf7pdqwpe0jtala.lambda-url.us-east-2.on.aws/ CustomDomain | https://pr321.billing.web3.storage - **pr321-w3infra-CarparkStack** Name | Value -- | -- BucketName | carpark-pr321-0 Region | us-east-2 - **pr321-w3infra-RoundaboutStack** Name | Value -- | -- ApiEndpoint | https://zs1a0syc2d.execute-api.us-east-2.amazonaws.com CustomDomain | https://pr321.roundabout.web3.storage - **pr321-w3infra-SatnavStack** Name | Value -- | -- BucketName | satnav-pr321-0 Region | us-east-2 - **pr321-w3infra-UploadApiStack** Name | Value -- | -- ApiEndpoint | https://f1nk7lf1va.execute-api.us-east-2.amazonaws.com CustomDomain | https://pr321.up.web3.storage - **pr321-w3infra-BusStack** - **pr321-w3infra-FilecoinStack** - **pr321-w3infra-ReplicatorStack** - **pr321-w3infra-UcanFirehoseStack** - **pr321-w3infra-UcanInvocationStack** - **pr321-w3infra-UploadDbStack**