cmd: update triangulate help command

[cpanato]

Summary

similar to #1058

update the cosign triangulate command documentation/help to align with the other commands and to fix some misalignments when using the help.

before

$ cosign
...
  sign-blob          Sign the supplied blob, outputting the base64-encoded signature to stdout.
  triangulate        Outputs the located cosign image reference. This is the location cosign stores the specified artifact type.
cosign triangulate <image uri>
  upload             Provides utilities for uploading artifacts to a registry
  verify             Verify a signature on the supplied container image
  verify-attestation Verify an attestation on the supplied container image
  verify-blob        Verify a signature on the supplied blob
  version            Prints the cosign version

Flags:
      --azure-container-registry-config string   Path to the file containing Azure container registry configuration information.
  -h, --help                                     help for cosign
      --output-file string                       log output to a file
  -d, --verbose                                  log debug output

after the change

$ ./cosign
...
  sign               Sign the supplied container image.
  sign-blob          Sign the supplied blob, outputting the base64-encoded signature to stdout.
  triangulate        Outputs the located cosign image reference. This is the location cosign stores the specified artifact type.
  upload             Provides utilities for uploading artifacts to a registry
  verify             Verify a signature on the supplied container image
  verify-attestation Verify an attestation on the supplied container image
  verify-blob        Verify a signature on the supplied blob
  version            Prints the cosign version

Flags:
      --azure-container-registry-config string   Path to the file containing Azure container registry configuration information.
  -h, --help                                     help for cosign
      --output-file string                       log output to a file
  -d, --verbose                                  log debug output

and the clean help

$ ./cosign triangulate --help
Outputs the located cosign image reference. This is the location cosign stores the specified artifact type.

Usage:
  cosign triangulate [flags]

Examples:
  cosign triangulate <IMAGE>

Flags:
      --allow-insecure-registry                                                                  whether to allow insecure connections to registries. Don't use this for anything but testing
      --attachment-tag-prefix [AttachmentTagPrefix]sha256-[TargetImageDigest].[AttachmentName]   optional custom prefix to use for attached image tags. Attachment images are tagged as: [AttachmentTagPrefix]sha256-[TargetImageDigest].[AttachmentName]
  -h, --help                                                                                     help for triangulate
      --k8s-keychain                                                                             whether to use the kubernetes keychain instead of the default keychain (supports workload identity).
      --type string                                                                              related attachment to triangulate (attestation|sbom|signature), default signature (default "signature")

Global Flags:
      --azure-container-registry-config string   Path to the file containing Azure container registry configuration information.
      --output-file string                       log output to a file
  -d, --verbose                                  log debug output

Ticket Link

n/a
Fixes

Release Note

cmd: update triangulate help command