Fix incomplete recommended configs

[MoOx]

This change allow you to extends "plugin:react/{something}" without having to do something more.
If you just extends one config, you get errors about missing rules definition.

[ljharb]

I'm not sure I understand - you extend configs, not rules or plugins. react/jsx-indent is a rule, not a config.

In other words, the only two configs that this plugin provides are "recommended" and "all", and that's intentional.

[MoOx]

I am not sure to follow your response.
The idea here is to be able to "just" do

{ 
  extends: "plugin:react/recommended"
}

But currently you need to do

{ 
  "extends": "plugin:react/recommended",
  "plugins": [ "react" ]
}

Otherwise your get error about unknown rules. It's pretty weird to register rules without adding definitions for those rules.
This issue is a follow up on MoOx/phenomic#838

[ljharb]

Wow, TIL. Thanks for explaining - I wasn't aware this was a feature of shared configs.

[yannickcr]

Merged, thanks!