Add Azure AI Foundry Community Discord and Developer Forum links to README

[Copilot]

This PR adds an "Additional Resources" section to the root README.md file with links to Azure AI Foundry community resources as requested in issue #32.

The new section includes:

• Azure AI Foundry Community Discord (https://discord.com/invite/kzRShWzttr)
• Azure AI Foundry Developer Forum (https://github.com/orgs/azure-ai-foundry/discussions)

The section is positioned at the end of the README after the Trademarks section and uses the same H2 heading style (##) as other sections in the document to maintain consistency with the existing structure.

Note: These links are different from the existing Azure AI Community Discord link already present in the README, as they point to the specific Azure AI Foundry community resources.

Fixes #32.

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