Promoted CLI Missing From API Reference Section

[speediedan]

Thanks for your immensely valuable contributions to the ML research community!

I've noticed that since the recent promotion of the cli out of utilities, the new location is missing its reference in the API Reference:

python -msphinx.ext.intersphinx https://pytorch-lightning.readthedocs.io/en/latest/objects.inv | grep "pytorch_lightning.*.cli.LightningCLI "

pytorch_lightning.utilities.cli.LightningCLI api/pytorch_lightning.utilities.cli.html#pytorch_lightning.utilities.cli.LightningCLI

I'm submitting a PR shortly to fix this issue by simply adding the new api location (in addition to the deprecated existing one) so that intersphinx references to the CLI can be updated to the new location and that the new location is properly reflected in the API Reference section:

python -msphinx.ext.intersphinx ../build/html/objects.inv | grep 'pytorch_lightning.*.cli.LightningCLI '

pytorch_lightning.cli.LightningCLI       api/pytorch_lightning.cli.LightningCLI.html#pytorch_lightning.cli.LightningCLI
pytorch_lightning.utilities.cli.LightningCLI api/pytorch_lightning.utilities.cli.html#pytorch_lightning.utilities.cli.LightningCLI
...

Thanks again!

cc @Borda @rohitgr7 @carmocca @mauvilsa