feature: Add support for Promise and allow other functions to wait for the return.

[DragonLiParadise]

Description: When I use this extension package, I find that I cannot determine how long it will take to return results. This is because the runWith method does not wait for the execution result. I am using a serverless Lambda architecture, and I hope that all my executions are predictable.

[kibertoad]

sorry, this has somehow slipped through the cracks, I'll check it out!