ci: don't run tests when markdown files are changed

[ErikSchierboom]

See https://github.com/ErikSchierboom/configlet/actions for a working example.

[ee7]

Nice.

LGTM, but I'd suggest we amend the commit message to something like

ci: don't run tests workflow for Markdown-only changes

with the body

To prevent the tests workflow from running unnecessarily we don't run it
when only Markdown files are changed

This adds the word "only" to both - the previous wordings imply that we don't run tests for any commit that includes a change to a .md file.

And nitpick: can we wrap the commit message body at 72 chars?

[ErikSchierboom]

I've updated the commit message.

And nitpick: can we wrap the commit message body at 72 chars?

With due respect, but I won't be doing this. We don't enforce this anywhere on Exercism and I personally don't feel that it offers much.

[ee7]

And nitpick: can we wrap the commit message body at 72 chars?

With due respect, but I won't be doing this. We don't enforce this anywhere on Exercism and I personally don't feel that it offers much.

No problem.

By the way, no need to force-push an amended commit if there's zero code change - I'd be fine if you added the "only" while you clicked "squash + merge".

[ErikSchierboom]

Ah okay.