Corrected projectID instruction message

[malay5]

What does this PR do?

This PR updates the error message for Project IDs to clarify that they are limited to 36 characters, with valid characters being a-z, 0-9, and non-leading hyphens. It ensures accuracy and clarity in the error message.

Test Plan

(Write your test plan here. If you changed any code, please provide us with clear instructions on how you verified your changes work. Screenshots may also be helpful.)

• Verified that the Project IDs validation matches the updated description.
• Checked for any rendering issues in the documentation.

Related PRs and Issues

Related issues:

#575
appwrite/appwrite#6467

Checklist

• Have you read the Contributing Guidelines on issues?
• If the PR includes a change to an API's metadata (desc, label, params, etc.), does it also include updated API specs and example docs?

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