#9352 docs(library): update what-is-an-mcp-server

Summary

• Refreshes the library post what-is-an-mcp-server (apps/sim/content/library/what-is-an-mcp-server/index.mdx).
• Title unchanged.
• A replacement article was merged into the existing post.
• Requested change: MERGE this hub expansion into the existing library post at library/what-is-an-mcp-server; do not swap out or overwrite the current article. Preserve every existing FAQ question verbatim unless a first-party source proves it wrong, every existing H2 and H3, every product compared, every outbound cita…

Generated by the Library Post PR Updater workflow. Not built or tested locally. After the PR opens, the workflow content gate checks changed paths, frontmatter keys, FAQ placement, and internal links; CI check:library-content validates the post once it is enabled.

• I confirm that I have read and agree to the terms outlined in the Contributor License Agreement (CLA)