Add FAQ section on plugin version numbering convention

[Xpirix]

Description

Closes #269

Author's checklist

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• my commits tend to comply with Conventional Commits; so they are descriptive and explain the rationale for changes. Messages and description are self-explanatory to make the git log a readable story of the project.
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• I have added necessary documentation (if appropriate).
• commits which fix bugs include Fixes #11111 at the bottom of the commit message.

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Reviewer's checklist

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