Add a pkcs11-tool/pkcs11-spy setup guide.
Add a pkcs11-tool/pkcs11-spy setup guide.

Formatting preview at: https://g3doc.corp.google.com/experimental/users/aburaggina/g3doc/libkmsp11_pkcs11spy_setup.md?cl=head

Change-Id: I16d8aa3328819128c0a934faed0aef5458cdca32

GoogleCloudPlatform/kms-integrations,GoogleCloudPlatform/kms-integrations,GoogleCloudPlatform/kms-integrations,GoogleCloudPlatform/kms-integrations,GoogleCloudPlatform/kms-integrations,GoogleCloudPlatform/kms-integrations