Fix docs - missing Trainer

[Borda]

What does this PR do?

Fixes missing Trainer docs.

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[pep8speaks]

Hello @Borda! Thanks for opening this PR.

• In the file pytorch_lightning/loggers/trains.py:

Line 219:101: E501 line too long (111 > 100 characters)

Do see the Hitchhiker's guide to code style

[awaelchli]

Do you know if it is possible to test the docs as part of the CI? Sometimes people don't check that the docs compile or don't see the warnings. Otherwise things like this will happen again and need to be fixed by someone else :(

[codecov]

Codecov Report

Merging #1159 into master will decrease coverage by <1%.
The diff coverage is 100%.

@@           Coverage Diff           @@
##           master   #1159    +/-   ##
=======================================
- Coverage      93%     93%   -<1%     
=======================================
  Files          61      61            
  Lines        2672    2670     -2     
=======================================
- Hits         2472    2470     -2     
  Misses        200     200

[Borda]

Do you know if it is possible to test the docs as part of the CI? Sometimes people don't check that the docs compile or don't see the warnings. Otherwise things like this will happen again and need to be fixed by someone else :(

yes, we already had this discussion before v0.7.1 but then there was much other work...
we already have it in CI but the problem is that these errors do not crash the building process
https://app.circleci.com/pipelines/github/PyTorchLightning/pytorch-lightning/1369/workflows/4123ff8a-8117-4ad5-83db-6e01d9e061ea/jobs/9335
I was checking for a solution which would raise warning as errors but has not found it yet
in our case, the problem is mostly in autodoc that it fails on bad imports or syntax...