docs: say when releases are cut, and that there is no fixed cadence

[hectorvent]

What does this PR do?

CONTRIBUTING.md described how a release is cut but never when. The four emulators now publish a 1st and 3rd Tuesday train in their READMEs and contributor guides; floci-cli is not on it, and its history says so (0.2.1 on Thu 2026-08-27, with irregular gaps before it).

Rather than leave the question open or imply a schedule nothing enforces, the section now opens by stating there is no fixed train, and that releases are cut when there is something worth shipping.

Em-dashes replaced with ordinary punctuation, matching the convention the four emulators adopted in their AGENTS.md.

Related issues

None. Follow-up to the release-train documentation work.

Checklist

• Commits are signed off for the DCO — not signed off; no DCO check runs on this repo and main's history is largely unsigned. Happy to amend if you want it.
• Commit messages follow Conventional Commits.
• No AI attribution in commit messages.
• Tests pass locally and new behavior is covered — not applicable, prose only.
• Docs updated if behavior or configuration changed.
• I have read the Contributing guide and agree to the Code of Conduct.

[greptile-apps]

Greptile Summary

Updates CONTRIBUTING.md to clarify that floci-cli releases have no fixed cadence and are cut when there is something worth shipping.

• Adds explicit release-cadence guidance for maintainers.
• Replaces em dashes with ordinary punctuation throughout the guide.

Confidence Score: 5/5

The documentation-only PR appears safe to merge with no actionable issues identified.

The release guidance is internally consistent with the existing workflow description, and the remaining edits are punctuation-only.

Important Files Changed

Filename	Overview
CONTRIBUTING.md	Documentation-only changes accurately clarify the release cadence and standardize punctuation without altering runtime behavior.

_{Reviews (1): Last reviewed commit: "docs: say when releases are cut, and tha..." | Re-trigger Greptile}