Fix: Add x5c parameter description to JWKS documentation for all affected versions (Product IS issue #19610)

[wso2-engineering-bot]

This PR was automatically generated by Claude AI.

• Issue: JWKS doc does not include the x5c param's description product-is#19610
• Type: Documentation
• Summary: Added missing x5c parameter description to the JWKS documentation table. The x5c parameter contains the X.509 certificate chain in base64-encoded DER format as specified in RFC 7517.
• Affected Versions: 6.0.0, 6.1.0
• Style Scope Verification: Microsoft Style Guidelines have been applied ONLY to newly added content (the x5c parameter description) without modifying existing content style unless specifically requested.

Changes made:

• Added x5c parameter row to the property table in both versions
• Included description following RFC 7517 specification
• Added reference link to RFC 7517 section 4.7 for additional details

Testing:

• Verified table formatting is consistent with existing structure
• Verified markdown syntax is correct
• Changes follow Microsoft Style Guide for new content

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