src/node/plugin.ts/PluginAPI/loadPlugins
class PluginAPI:  public async loadPlugins(loadBuiltin = true): Promise<void> {
    for (const dir of this.csPlugin.split(":")) {
      if (!dir) {
        continue
      }
      await this.loadPlugin(dir)
    }

    for (const dir of this.csPluginPath.split(":")) {
      if (!dir) {
        continue
      }
      await this._loadPlugins(dir)
    }

    if (loadBuiltin) {
      await this._loadPlugins(path.join(__dirname, "../../plugins"))
    }
  }