Mis formatted MCP example in docs due to nested codefence

[tspascoal]

In HTTP MCP servers example with authentication headers there is a nested yaml wrap codefence that is nested inside another codefence which results in mis formatted text.

There is also an (almost) duplicated description inside the codefence that should be deleted.

Plan to fix (nested fence)

1. Edit docs/src/content/docs/guides/mcps.md to remove the nested code fence (and the almost duplicated description)
2. Restructure :
   • Delete the explanatory sentence inside the code fence and delete the inner code fence
3. Expected corrected shape (conceptually):
   • One ```yaml wrap block containing only YAML
4. Validate by previewing the docs page to ensure the section after this renders normally and the YAML block is highlighted correctly.
5. Search for similar nested fences and list them so a human can decide on the best course of action