docs: clarify permissive-in strict-out naming policy

[Rohan5commit]

Summary

Add a short "Input and output handling" subsection to the Graph naming guidelines to document a permissive-in / strict-out policy for naming variants.

Related issue

Fixes #571

Guideline alignment

Read CONTRIBUTING.md and targeted the vNext branch with a focused one-file documentation change.

Validation

• git diff --check

[Copilot]

Pull request overview

Adds guidance to the Microsoft Graph naming section to document a “permissive-in / strict-out” approach when services accept multiple input variants but produce a single canonical output form.

Changes:

• Adds an “Input and output handling” subsection under Naming.
• Defines guidance for accepting equivalent input forms while emitting canonical outputs.
• Requires documentation to describe canonical outputs and accepted variants.

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[Copilot]

The bullet says services MUST emit a single canonical form "in responses, notifications, and examples". Services don’t emit documentation examples, so this mixes responsibilities. Consider limiting the service requirement to runtime outputs (responses/notifications) and moving the examples requirement to the documentation bullet below (or rephrasing it as "Documentation examples MUST use the canonical form").

Suggested change

	- Services **MUST** emit a single canonical form in responses, notifications, and examples so customers see one stable shape on output.
	- Documentation **SHOULD** call out both the canonical output form and any accepted input variants whenever the service intentionally accepts more than one form.
	- Services **MUST** emit a single canonical form in responses and notifications so customers see one stable shape on output.
	- Documentation **SHOULD** call out the canonical output form, use the canonical form in examples, and describe any accepted input variants whenever the service intentionally accepts more than one form.