Verify demos

Prerequisites

• [X] I am running the latest version of the AEA Framework.
• [X] I checked the documentation and found no answer to my problem.
• [X] I checked the existing issues to make sure my problem has not already been reported.
• [X] I have read the code of conduct before creating this issue.

Expected Behavior

All demoes are up to date and runnable

Current Behavior

We don't know if all demoes are up to date and correct w.r.t. the latest framework and packages

To Reproduce

No response

Context

All

Failure Logs

No response

WIP DOC: https://docs.google.com/document/d/1khTLwl-DQsHF8cNtP42wDukNhr9-R-AL_P1vLZUkDAQ/edit?usp=sharing

To be redone after next AEA hotfix due to package inconsistencies between repo and registry

• [x] Add preliminary commands for Tensorflow
• [x] Update gym skills readme