Fix ROUGE add example check and update README
# What does this PR do?

This PR contains a few fixes for the examples all linked to #18381 
- it adds the version check of Transformers to the `no_trainer` examples, so that the user is not surprised when the example script that uses main fails if they use a different version
- it expands the table of examples for each version to get to the current version
- it fixes the ROUGE metric return type since that metric was broken in https://github.com/huggingface/evaluate/pull/158

Fixes #18381
_The documentation is not available anymore as the PR was closed or merged._<|||||>Failures are flaky, so merging.