Expose extras from mono-repo packages on lightning

[nicolai86]

🚀 Feature

today, we have extras ie, lightning_app[cloud], which can't be installed when lightning is installed directly.

Motivation

Exposing the extras on lightning would make the installations more straight forward.

Pitch

Expose sub-package extras on lightning, so ie pip install lightning[cloud] works.

Alternatives

Additional context

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If you enjoy Lightning, check out our other projects! ⚡

• Metrics: Machine learning metrics for distributed, scalable PyTorch applications.

• Lite: enables pure PyTorch users to scale their existing code on any kind of device while retaining full control over their own loops and optimization logic.

• Flash: The fastest way to get a Lightning baseline! A collection of tasks for fast prototyping, baselining, fine-tuning, and solving problems with deep learning.

• Bolts: Pretrained SOTA Deep Learning models, callbacks, and more for research and production with PyTorch Lightning and PyTorch.

• Lightning Transformers: Flexible interface for high-performance research using SOTA Transformers leveraging PyTorch Lightning, Transformers, and Hydra.

cc @carmocca @akihironitta @Borda