Issue 38 has training resource

[katiestahl]

close #38
add new slot for has_training_resource

[katiestahl]

@caufieldjh I have no idea what happened here but there are a loooot of changes I wasn't anticipating after running make all. Did I do something wrong? I'm not sure why a bunch of whitespace was changed, and some unused imports were automatically added to standards_schema_all.py 😭 Is this expected? If not, how else should I regenerate the files necessary to go along with this PR?

The actual changes I made are here: 6173b28

[caufieldjh]

Thanks! Looks good!

[caufieldjh]

Those are all expected changes. Most of them are autogenerated, and the unused imports are just a result of the way LinkML templates python classes. Should only cause issues if a linter is configured to run on them, and I don't think it is in this repo.
Most of the generated updates are to the docs and there's some redundancy here because they're getting copied to /docs from the /project directory, but nothing harmful there.