[doc] Add docs of referential AWS IAM policies with least privilege for Piped

[t-kikuc]

What would you like to be added:

• Add docs of referential AWS IAM policies with only required permissions.

• Target platform to deploy:

  • ECS
  • Lambda

• NOTE: Required permissions will be updated in the future.

• [IMO] It might be better to create some patterns because required permissions are varied between QuickSync and Canary&Blue/Green (even though users' operations will be tough)

Why is this needed:

• Users can limit permissions of piped, not FullAccess.
• However, currently it's difficult to specify which actions are necessary for deployments.