Fix typos in documentation and JSON spec

[vtjl10]

Description:
This pull request corrects minor typos in two files:

• In packages/tasks/src/tasks/placeholder/spec/output.json, the word "outputed" was corrected to "outputted" in the description field.
• In packages/tasks/src/tasks/reinforcement-learning/about.md, the word "evalute" was corrected to "evaluate" in the explanation of the training cycle.

[Vaibhavs10]

Thanks for fixing the typos!