Update identity guardrail language to add clarity

[nhecht]

Issue in ./help/identity-service/guardrails.md

experience-platform.en/help/identity-service/guardrails.md

Line 33 in 864aae4

| Number of links to an identity for a single batch ingestion | 50 | A single batch could contain anomalous identities that cause unwanted graph merges. To prevent this, Identity Service will not ingest identities that are already linked to 50 or more identities. |

The following line creates some ambiguity on how this is handled.

I have followed up with Engineering to confirm the behavior.

Suggest the Notes be updated to say the following.

"If a single identity in a batch is linked to 50 or more other identities in the batch, the identity is considered invalid, and will be filtered out of the batch linkages."

This is more clear then the current language.
"A single batch could contain anomalous identities that cause unwanted graph merges. To prevent this, Identity Service will not ingest identities that are already linked to 50 or more identities."

One could interpret the above to mean if the identity already had 50 linkages in the prior ingested graph. But the batch identity ingestion process makes no reference to the prior ingested graph status.

[vfalon]

Thank you for submitting this issue. We will review the documentation and make the necessary updates as quickly as possible. Tracking internally in PLAT-229027.