Support eslint flat-config

[GNRSN]

Is your feature request related to a problem? Please describe.
We're opting in to the new eslint flat config which includes many benefits, for our case especially as it allows extending lint-configs in a monorepo without having to install the plugins everywhere. Something which previously required a patch from Microsoft rushstack

Describe the solution you'd like
For eslint-plugin-storybook to offer flat-config versions of the included configs, e.g. recommended and csf-strict

Describe alternatives you've considered
I am currently re-mapping the properties of the configs to work with the flat-config object/array, but this might break with any new version os eslint-plugin-storybook

Additional context
See the eslint documentation for info about flat config. The feature has been in development preview since last year and is now considered stable. From my understanding it will soon be the new standard moving forward.

[osmestad]

Duplicate of #135 I think?