Docs: Plugin shareable config section does not mention that rules need to be prefixed with plugin name

[platinumazure]

The plugin config section in Working with Plugins does not mention that plugin rules listed under the configurations must be prefixed with the plugin name (full or short). This should probably be remedied. (The example just uses the core rule semi.)

It might not hurt to mention that plugin rules and core rules can be mixed in these configuration exports, either (with the caveat that, again, plugin rules must be prefixed). I think I had assumed that all rules exported from a plugin config must be plugin rules and so didn't necessarily need a prefix.