Add a {{ main_version }} expression #591
Description
Description
Similar to the utility of a {{ license }} expression, this expression can have complexity to derive which would make it useful to offer.
See full details here: #587 (comment)
Alternatively {{ image_version }} might also be apt, depending on context (it's considered main in source code, but associated to the image.version output and default for image.version in OCI labels/annotations).
NOTE: This might be a bit tricky as a global expression given it must not be used for the first enabled (after priority sorting). I'm not sure how useful it'd be within the tags input anyhow 😅