addErrorSeverity() {
		const severity = 2;

		this.ruleConfigs = this.ruleConfigs.map(config => {
			config.unshift(severity);
			return config;
		});

		// Add a single config at the beginning consisting of only the severity
		this.ruleConfigs.unshift(severity);
	}
Add a severity level to the front of all configs in the instance.
This should only be called after all configs have been added to the instance.
@returns {void}