Specify that the needed edition for the FCBIS functionality is PRO

[sleto-it]

It is important to mention that the needed edition for the FCBIS functinality is PRO, otherwise it is not clear if one starts reading directly from https://docs.percona.com/percona-server-for-mongodb/7.0/fcbis.html.

I implemented the text it in a similar way we did in https://docs.percona.com/percona-server-for-mongodb/7.0/fips.html

Thanks!

[Copilot]

Pull Request Overview

This PR clarifies that the File Copy Based Initial Sync (FCBIS) functionality requires the PRO edition of Percona Server for MongoDB. The change ensures users understand the edition requirement before attempting to use this feature.

• Updates the version admonition to include PRO edition requirement
• Modifies the introduction to specify PRO edition availability
• Adds clarification about PRO edition availability and alternative source code build option

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[Copilot]

The word 'functinality' in the PR description appears to be a typo and should be 'functionality'. While this doesn't affect the code change itself, it's worth noting for future reference.