Thanks! I think we need to also bump the minimum Hugo version to 0.141.0 inside config/_default/module.toml.

From the 0.141.0 release notes:

tpl/tplimpl: Deprecate twitter shortcode in favor of x shortcode gohugoio/hugo@1191467 @jmooring gohugoio/hugo#13214

Thanks!

You are welcome!

I think we need to also bump the minimum Hugo version to 0.141.0

Hmm, not sure about this. This PR uses the new x shortcode only onde in content/blog/rich-content.md. When using the theme as module, we do not mount the content folder, so I wouldn't expect that the use of the shortcode causes hugo to throw an error. I haven't tested this, though.
Please note my other PR #350. This PR requires minimum Hugo version of 0.141.0, so if you decide to merge this PR, we can stop discussing here 😄.