Display Psalm version on https://psalm.dev/ sandbox

[alies-dev]

There is no Psalm version info on https://psalm.dev/

Version info is important to know when to test code-snippet before submitting in issue to this repository

[danog]

The version is present in the expanded mode:

[alies-dev]

thanks! That's pretty good, better to see version number + commit hash, but I can live with it :)