Update links to latest PL docs (#17031)

Author: awaelchli

README.md

@@ -395,6 +395,6 @@ Lightning is also part of the [PyTorch ecosystem](https://pytorch.org/ecosystem/
 
 If you have any questions please:
 
-1. [Read the docs](https://pytorch-lightning.rtfd.io/en/latest).
+1. [Read the docs](https://lightning.ai/docs/pytorch/latest).
 1. [Search through existing Discussions](https://github.com/Lightning-AI/lightning/discussions), or [add a new question](https://github.com/Lightning-AI/lightning/discussions/new)
 1. [Join our slack](https://www.pytorchlightning.ai/community).

docs/source-pytorch/_templates/theme_variables.jinja

@@ -3,16 +3,16 @@
   'github_issues': 'https://github.com/Lightning-AI/lightning/issues',
   'contributing': 'https://github.com/Lightning-AI/lightning/blob/master/.github/CONTRIBUTING.md',
   'governance': 'https://pytorch-lightning.readthedocs.io/en/latest/governance.html',
-  'docs': 'https://pytorch-lightning.rtfd.io/en/latest',
+  'docs': 'https://lightning.ai/docs/pytorch/latest/',
   'twitter': 'https://twitter.com/LightningAI',
   'discuss': 'https://www.pytorchlightning.ai/community',
   'tutorials': 'https://pytorch-lightning.readthedocs.io/en/latest/#tutorials',
-  'home': 'https://pytorch-lightning.rtfd.io/en/latest/',
+  'home': 'https://lightning.ai/docs/pytorch/latest/',
   'get_started': 'https://pytorch-lightning.readthedocs.io/en/latest/starter/introduction.html',
-  'features': 'https://pytorch-lightning.rtfd.io/en/latest/',
+  'features': 'https://lightning.ai/docs/pytorch/latest/',
   'blog': 'https://lightning.ai/pages/blog/',
   'resources': 'https://pytorch-lightning.readthedocs.io/en/latest/#community-examples',
-  'support': 'https://pytorch-lightning.rtfd.io/en/latest/',
+  'support': 'https://lightning.ai/docs/pytorch/latest/',
   'community': 'https://www.pytorchlightning.ai/community',
   'forums': 'https://lightning.ai/forums/',
 }

src/pytorch_lightning/README.md

@@ -382,6 +382,6 @@ PyTorch Lightning is also part of the [PyTorch ecosystem](https://pytorch.org/ec
 
 If you have any questions please:
 
-1. [Read the docs](https://pytorch-lightning.rtfd.io/en/latest).
+1. [Read the docs](https://lightning.ai/docs/pytorch/latest).
 1. [Search through existing Discussions](https://github.com/Lightning-AI/lightning/discussions), or [add a new question](https://github.com/Lightning-AI/lightning/discussions/new)
 1. [Join our Slack community](https://www.pytorchlightning.ai/community).