Fix broken docs links noted in issue #609 ("Use case code examples" from "Building Generative AI Applications Using Amazon Bedrock" Amazon Skill Builder course)

[tyreer]

Issue #, if available:

#609

Description of changes:

This PR fixes issue #609 by updating broken links that were caused by the repository restructuring in commit ec95d56
(October 2024), which moved content from agents-for-bedrock to
agents-and-function-calling/bedrock-agents.

Changes made:

• Updated links in documentation files that referenced the old path structure
• Fixed links to the fine-grained access permissions example, which moved to a new location
• Updated navigation links in articles-guides/README.md to use proper relative paths

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