Introduce beta example for deploying on DigitalOcean App Platform using 1Password CLI and deprecate current App Platform example

[ag-adampike]

This PR introduces a beta deployment example that uses the DigitalOcean shell plugin with 1Password CLI to deploy 1Password SCIM bridge on DigitalOcean App Platform.

It also deprecates the current App Platform deployment example in favour of this one to reduce cost and complexity and increase speed of deployment.

Reasons to use this deployment example are detailed in the README, but to summarize:

• For standard deployments, App Platform will host SCIM bridge for a predictable cost of $10 USD/month (at the time of last review).
• There is no need to set up a DNS record. DigitalOcean automatically provides a URL for SCIM bridge.
• 1Password SCIM bridge deploys directly to DigitalOcean from a local terminal. There is no requirement to clone this repository for this deployment.

The deployment example also serves as a practical example of several op commands and deploys in seconds.

[ag-adampike]

In the most recent commit, the GitHub links throughout README.md won't work until this is merged to master, but they can be replaced with the path to this branch for review (i.e. use https://raw.githubusercontent.com/1Password/scim-examples/pike/do-app-platform-op-cli/beta/do-app-platform-op-cli/op-scim-bridge.yaml).

[ag-adampike]

The shell plugins side of things looks good to me!

Thanks for the review, @accraw! 😊