docs: Add Plugin Metadata in Terminology

[kayx23]

Current State

Plugin metadata doesn't have an associated doc under Terminology

Desired State

Perhaps plugin metadata should have its own doc in terminology too?

[pottekkat]

We can, but IMO, we don't need it because we mention the metadata available for each Plugin in the corresponding Plugin docs. Metadata doesn't have a different meaning here.

Plugin Config needs to have a section here because it is a concept specific to APISIX.

If more people find that this is missing in the docs, we can add it.

[kayx23]

Here I was referring to the metadata object one can create with the admin API. It has a "global" effect on plugin instances of the same name.

Metadata properties set at the plugin level is more granular and has a higher priority over the "global" metadata object. I don't know where this concept was explained in the current doc.

This was before this doc was written https://docs.api7.ai/apisix/key-concepts/plugin-metadata

[pottekkat]

@kayx23 Thanks for clearing that. Makes sense to add it.

[smileby]

@pottekkat @kayx23
Hi, I have made additions to the document and submitted a pull request. Could you please review it to see if there are any issues? Thank you very much.

Add Plugin Metadata in Terminology #10702