static getRuleNumericSeverity(ruleConfig) {
		const severityValue = Array.isArray(ruleConfig)
			? ruleConfig[0]
			: ruleConfig;

		if (severities.has(severityValue)) {
			return severities.get(severityValue);
		}

		if (typeof severityValue === "string") {
			return severities.get(severityValue.toLowerCase()) ?? 0;
		}

		return 0;
	}
Normalizes the severity value of a rule's configuration to a number
@param {(number|string|[number, ...*]|[string, ...*])} ruleConfig A rule's configuration value, generally
received from the user. A valid config value is either 0, 1, 2, the string "off" (treated the same as 0),
the string "warn" (treated the same as 1), the string "error" (treated the same as 2), or an array
whose first element is one of the above values. Strings are matched case-insensitively.
@returns {(0|1|2)} The numeric severity value if the config value was valid, otherwise 0.