Update installation instructions for Synapse packages on FreeBSD

[atagtm]

Fixed pkg version for FreeBSD

Pull Request Checklist

• Pull request is based on the develop branch
• Pull request includes a changelog file. The entry should:
  • Be a short description of your change which makes sense to users. "Fixed a bug that prevented receiving messages from other servers." instead of "Moved X method from EventStore to EventWorkerStore.".
  • Use markdown where necessary, mostly for code blocks.
  • End with either a period (.) or an exclamation mark (!).
  • Start with a capital letter.
  • Feel free to credit yourself, by adding a sentence "Contributed by @github_username." or "Contributed by [Your Name]." to the end of the entry.
• Code style is correct (run the linters)

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[MadLittleMods]

How can I cross-reference this package name?

https://ports.freebsd.org/cgi/ports.cgi?query=matrix-synapse&stype=all&sektion=all shows py311-matrix-synapse-1.138.0_2 and when clicking on it, I see py-matrix-synapse in the URL

https://www.freshports.org/net-im/py-matrix-synapse/ shows py-matrix-synapse. I do finally see py311-matrix-synapse as a "package flavor" available.

Should we just suggest the default py-matrix-synapse

[atagtm]

The package (py311-matrix-synapse) does not exist in the (default) quarterly repository, it's in "latest". The port is net-im/py-matrix-synapse

[MadLittleMods]

Per the 'Pull Request Checklist' in the PR description, this PR needs a changelog:

• Pull request includes a changelog file. The entry should:
  • Be a short description of your change which makes sense to users. "Fixed a bug that prevented receiving messages from other servers." instead of "Moved X method from EventStore to EventWorkerStore.".
  • Use markdown where necessary, mostly for code blocks.
  • End with either a period (.) or an exclamation mark (!).
  • Start with a capital letter.
  • Feel free to credit yourself, by adding a sentence "Contributed by @github_username." or "Contributed by [Your Name]." to the end of the entry.