docs: fix AEP TEE documentation typos

[tharune]

Summary

• Fix the malformed Canonical TDX README link in AEP-65 by removing the trailing space from the Markdown URL
• Normalize capitalization in the Intel/AMD TEE prerequisite references
• Fix a grammar typo in the near-term TEE implementation section

Verification

• Confirmed the Canonical TDX README URL returns HTTP 200
• Confirmed the AMD SEV README URL returns HTTP 200
• Ran git diff --check
• Confirmed the old malformed-link and typo patterns are no longer present

[tharune]

Closing this here because the AEP content lives in the AEP repository. Recreated in the correct repo: akash-network/AEP#102