Add "tenant", "labels_as_tags", and "descriptors"

[Nuru]

what

• Add additional label and id component: tenant
• New input labels_as_tags controls which labels are exported as tags
• New input descriptor_formats generates new output descriptors
• Update README, remove link to obsolete terraform-terraform-label

why

• Support users that host resources on behalf of and/or dedicated to single customers
• Supersedes and closes #131, giving people control over which tags the module generates
• Simple mechanism for creating multiple identifiers from the same inputs, reducing the need to create multiple instances of null-label
• Document tenant, labels_as_tags, descriptor_formats, add additional clarification, stop promoting obsolete module

[osterman]

/test all

[Nuru]

/test all

[korenyoni]

/test all

[Nuru]

/test all

[Nuru]

/test all

[Nuru]

/test all