* fix: update checker
- fixed bug where it would make the request to uptime.kuma.pet regardless of the `checkUpdate` config;
- defined constants in the top of the document for easier configuration/documentation;
- removed unnecessary compareVersions: we were comparing the same var on both sides res.data.beta, so it will always be equal.
* improvement: better logging and added doc
* improved UPDATE_CHECKER_INTERVAL_MS const
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Co-authored-by: Louis Lam <louislam@users.noreply.github.com>