docs: add docs for http-dubbo plugin

[kayx23]

Current State

Looks like it was decided in the feat PR to split out the doc task: #10703 (comment)

That was two months ago and there doesn't seem to be any doc as of now.

Desired State

Should have some docs.

[sunheyi6]

Is this plugin need to test using tengine? If so, there are some problems with the installation of tenginte. I have tried several methods, but none of them can be installed. I am unable to test what the final result is.

[kayx23]

I have no idea, but it's good to share here what you have tried/worked/not worked, so that other people picking this task up can reference.

[kayx23]

Hi @ShenFeng312 are you available some time to add some doc for http-dubbo plugin?

[ShenFeng312]

@kayx23 Sorry for the delay. I'll add the documentation as soon as possible.

[ShenFeng312]

Is this plugin need to test using tengine? If so, there are some problems with the installation of tenginte. I have tried several methods, but none of them can be installed. I am unable to test what the final result is.

This plugin does not require Tengine.