interpreters: document status, fix outdated cmds

[mralusw]

Since the actual status is a bit different from what the docs say, they should be updated. If you think more clarifications are needed, let me know.

To test the release-notes script (where missing a backslash can wreak havoc),

bash ./scripts/release_notes.sh >x.md
mdview x.md

This will of course not perfectly generate the text / links which require GitHub Actions, but those are untouched. Updated: running the script under sh doesn't flag a missing EOF.

[mralusw]

force pushed:

• +python3/dyn-stable not +python3/dyn
• missed the final EOF

[chrisbra]

thanks!