Update Learning-Environment-Executable.md

[RedTachyon]

[docs]

Updated the command to run an example training (trainer_config.yaml instead of ppo/3DBall.yaml)

Proposed change(s)

The command was outdated, presumably the configs were refactored some time ago.

Useful links (Github issues, JIRA tickets, ML-Agents forum threads etc.)

Types of change(s)

• Bug fix
• New feature
• Code refactor
• Breaking change
• Documentation update
• Other (please describe)

Checklist

• Added tests that prove my fix is effective or that my feature works
• Updated the changelog (if applicable)
• Updated the documentation (if applicable)
• Updated the migration guide (if applicable)

Other comments

[CLAassistant]

All committers have signed the CLA.

[harperj]

Hi @RedTachyon -- these references in the docs are correct for the master branch, which is under active development. You can find the docs for Release 1 here.