async start(enable = false) {
        await this.process.start(this.dir, this.system.environment);
        this.setRunningMode(this.system.environment);

        if (!enable) {
            return;
        }

        const isEnabled = await this.process.isEnabled();
        if (isEnabled) {
            return;
        }

        await this.process.enable();
    }
Starts the Ghost instance

@return {Promise<void>}
@method start
@public