[eamsden]

What was changed

Add the following policy after the introductory paragraphs in an IMPORTANT callout in CONTRIBUTING.md:

Non-Temporal contributors must not solicit user or customer information, including but not limited to workload, use-case, or failure information. Doing so will result in a ban from all Temporal repositories at Temporal's sole discretion.

Why?

Make the restriction on non-Temporal contributors soliciting user or customer information, and the consequence for doing so, explicit at the start of the contribution guide.

Checklist

1. How was this tested: Verified that the requested wording appears verbatim after the introductory paragraphs in an IMPORTANT callout and that all other file contents are unchanged. SDK tests were not run for this documentation-only change.
2. Any docs updates needed? This PR updates the contributor guide.

Breaking changes?

No SDK runtime or public API changes.

Server PR

Not required.